What is a Content Library and How to Build it?

Introduction – What is a Content Library?

The Content library is a collective of all content assets owned by a company that is placed in an internal portal or website. In other words, the content library is full of resources that you want your audience /customers to know about the product or services you are providing.

A Content library may include all the information and news about the product/service of the company in the form of articles, blogs, infographics, images, videos, etc. 

Writers may probably know, the more you write and publish, the more your products reach customers.

So to create a content library on your website all you need to do is write, post and repeat. You should post much as content as you can. The one important thing to keep in mind is the content should be original, unique, and engaging.

Struggling with content production, learn the properties of viral content and come up with your own killer content.

Let’s get into business- Content Library

How to create a content library on your website?

As we said before it is about writing and posting. The writer/content creator should be aware of what to write, how to write, and when to post. It is essential to keep yourself up-to-date about the news, events, and current affairs. This is just the basic of content library.

Collect as much information as possible to create content on the topic which is relevant to your company’s products/services. With the collected information make a rough draft of the content with interesting media. While writing, think from the reader’s point of view. It will help you to keep the content engaging and productive. 

The copy you have created must be indeed proofread and edit if needed. In this stage you can omit any unwanted information added, clear grammatical errors if any, and finally, make sure you have error-free excellent content to post on your content library.

Once your content is ready and all set for publishing choose a template that is suitable for your website and post the content to the library. You always need to keep checking which content should need updating and revising to match the keyword searches in the search engines. 

Creating a content library is indeed essential for promoting the products and business digitally. It will help to increase the reach of products/services to more customers and thereby enhances business growth. 

Let’s now look at the types of content that you can add in your content library.

Types of Written Content for Content Library

There are many types of written content you can share online. When you are a digital marketer or when you want to do content marketing online, you can use the following content types and gain more reach.

Web Content

• Any content written for publishing on a website is called web content. It includes the home page, About us page, contact page, and other web pages on your website. 

• Web content is seen as a great platform for companies to connect with their potential customers/viewers.

• Without a website/any web content, any online promotion you make is going to be ineffective. 

• Web content needs to be unique, original, and engaging.

• Content writers should also use relevant keywords for SEO. 

• A good web page content should be about the customer, their requirements/interests, etc, rather than just being about the company’s product/brand.

Blogging

• Blogging is seen as the next important step for optimizing your web content. 

• Blogs are a great source of providing interesting, conversational, and engaging content.

• Even SEO practices can be easily implemented while blogging.

• Blogs are a great way to attract more viewers to the website and are also a brilliant source for converting potential consumers to actual customers. 

• It is important to be a regular blogger/post blogs regularly, to stay consistent and keep the audiences engaged.

• One can use blogs to deliver the primary essence of who they are, what do they do, and other similar content. 

• There are no fixed formats for a blog. However, the common types are ‘How to do it?’ ‘What to avoid?’ ‘Why not do this than that?’ etc.

• A common method of writing a blog for SEO is by having 4 sub-headings, a catchy and relevant heading/title, and short and crisp content. 

• Use blogs to build brand awareness and achieve SEO rankings.

• There’s also something called Microblogging which restricts the writer to 140-150 words while a blog has no such restrictions.

Social Media

• It is not only important to have a website to boost your business/brand image but is equally significant to have a strong social media presence. This is because nowadays many potential consumers/viewers are all highly using social media.

• Major social platforms like Twitter, Facebook, Instagram, Pinterest, etc are all the top places that one searches to know about a brand and their culture/voice. 

• Keeping the content engaging, unique, and original in a company’s social media platforms is a great way to attract more customers to your business.

• Start events, message your customers directly, and make regular blog posts to keep your viewers engaged. 

• While writing for social media platforms, use short sentences, hashtags, emojis, and sometimes an informal tone to develop a sense of personal touch. 

Ad and sales copy

• These are also part of marketing your brand and its services/products. However, the major difference is, these Ad copies are used for showcasing the uniqueness of your brand.

• These copies need attractive taglines, short sentences with apt content. Attractive images are also important here.

• These copies can be posted on social media (mostly).

• Sales copy of a business/brand should be developed after building an audience and gaining their trust through better customer services and supply of quality products/services.

• Keep your Ad/Sales copy like an approachable message for a friend and not like a formal letter.

• The content of these copies should not be misleading/manipulative, instead, it should be true and should be subjected to the right audience at the right time.

• These are also called Sales copywriting.

Expert, or industry writing

• As the name suggests, an expert content writer will be aware of the company and all of its niches’ nuances. This is why a company depends on such expert ghostwriters to write for their blogs, to showcase their company’s different activities, characteristics, etc.

• The special feature of an expert/industry writer is how they take the voice of the company, adapt to that tone, and then deliver the message in the form of blogs and others.

• This is a critical writing requirement for any company, as, without a proper description of who they are and what they do, people will not be interested in them.

• Expert writing also deals with writings drafted professionally. Writers induce expert quality to the content they write, leading to better reach and engagement. (SEO, Google Ranks, etc.)

• These writers should not only be aware of the company’s features but also of the relevant industry as a whole. 

Journalistic/news and PR writing:

• These writings are usually treated as news writing as they share news of any new product launch/new brand launch/any newsworthy events conducted by companies, etc.

• The main purpose of these writings is to share the company’s news to the general public, through a trustworthy source.

• Writings like press releases, social media messages, brochures, fact sheets, blog posts, featured articles, etc are the primary work of a PR (Public Relations) expert.

• These writings are usually formal and are addressed to the general public. 

• Share content that is newsworthy, not just some simple events with no much significance.

• The content you share must boost your company’s brand image. 

Creative Writing

• Writings that are very creative, fresh, unique, engaging, and original are creative writings. Eg: Speeches, poems, taglines, etc.

• Keep your marketing copy creative. Your social media, blogs, web content, ads, etc, need to be creative, to make it different and engaging. Even a tweet you make can be creative.

• These writings show the real talent of writers who use their creative knowledge to share particular/common information. 

• It is important to have the best creative writers for your company’s writings purposes, to boost your brand image through engaging content.

• Creative writers add colors to normal texts.

Case Studies

• Case studies are used by marketers/companies to boost their brand image and trust by sharing their customer stories. 

• These stories will talk about how good a company’s products/services are and how the customer got benefited by it, etc.

• Testimonials are also a great form of the case study.

• Case studies bring real-life examples which will boost a company’s goodwill and trust.

• Use quotes, statistics, etc, to illustrate the merits of your business.

eBOOKS

• eBooks are the new trend as everything has been shifted to the digital platform.

• You can use these ebooks to build a relationship with your customers/viewers rather than doing just a promotion for sales. 

• Content for ebooks can either be freshly written or the already existing blog posts can be packed into an ebook and be sold.

• People can access your ebook content only after they enter some information about them, like registers/signups, etc. This builds a chance for communicating with your potential customers in the future.

• Keep your content rich in information.

White Papers

• White papers are also content that carries information about your business/company. 

• These also focus on details and data, even more than ebooks.

• Mostly used by B2B industries

• Used for gaining respect within your industry and sometimes when your white papers get popular, your company’s good name will spread.

• Keep your white papers gated for gathering useful contact information as ebooks do. 

Types of Audio Content for Content Library

Your content library can also have audio content.

Audio content was very popular before video content came into existence. Radio communication is the best example of audio content. However, now-a-days, people look up to Google for most of their questions and so even the content producers have shifted their supplies to the online media. 

Podcasts

• Audio contents are now gradually growing and the most popular ones are Podcasts.

• You can share useful, thought-provoking content with audiences through podcasts.

• Used for brand awareness, building relationships with the audience, promoting products and services, and music/songs.

• Do not make your podcasts as a sales pitch but make it interesting and rich in valuable content (relevant to your business/brand).

• Podcasts support only audio and not video.

• However, keep your podcast posters unique and attractive to have more listeners to your podcasts.

• Record your podcasts with real human voices, keep the script with a conversational tone/use natural language, and keep the quality of your audio pitch-perfect.

• Produce the script of your podcasts to attract even more audiences and develop your podcast’s SEO.

• Understand that the audiences of podcasts are mostly educated and sophisticated people.

• Do not make your scripts too regular/as the usual marketing type, instead approach your audiences with a different angle which will not seem like promoting only your products/services. Eg: If you are a company that produces career guidance, then you can make podcasts on general topics related to career guidance. You can make it as a motivational audio clip rather than a sales promoting clip.

• You can also address the issues of the industry you are dealing with, rather than just your company.

Audio Books

• These are called ‘books-on-tape.

• These are a great way of storytelling.

• As a marketer, you can convert your company’s ebooks into audiobooks for more reach and convenience. 

• You can improve your content marketing strategy through these audiobooks.

Voice Search

• Through a virtual assistant device/smart speakers, voice searches are made possible. These voice searches are used for tailoring ads for searching, leading to voice search optimization.

• These voice searches reduce the time and effort required to type the words.

• Google, Alexa, etc are the best examples of this.

• Alter your keywords as per how your customer voice search for your products/services.

• For any content, these voice searches can be optimised, for better SERP ranks for your website/ web content.

Audio Advertisements

• These are quite common in apps like Spotify/Gaana, etc. However, these are still improving.

• Even Alexa or Google include an audio-advertising element, but these are not practically possible yet.

• Promoting Podcasts are also a great way of reaching out to potential customers.

• However, video ads are still stronger.

Types of Image Content for Content Library

Text ads are always important but in this growing digital era, a visual representation of any content, especially ads is important. These image contents can be persuasive too.

Infographics

• Infographics are nothing but data presented in an easy to understand format which includes clear images, simple words and short statements. 

• Mostly use it to promote any educational/complex topics, to make your audience understand your content better.

• Infographics are used for better visualization of content.

• Even large amounts of information can be easily conveyed using these infographics.

• These are only one-paged content.

Images

• As the attention span is very short now-a-days, images pave a great way to communicate/convey relevant information within a short time.

• Always use high-quality images.

• Just like content, make sure your images are unique and original (in most cases) to improve your on-page content for SEO.

• You can use apps like Canva, Adobe, etc to create attractive posters, banners, logos, etc.

• Use alt tags for the images you post online to avoid any plagiarized image content.

Memes

• The new trend is to create memes for fun (mostly).

• These memes make their content viral in no time. 

• These promote their content faster than other modes.

• Memes are nothing but an image with a funny caption.

• Though was first used by students for fun, even marketers use memes to promote their company’s brand.

• When you create your own meme, you can evoke positive emotions and set yourself apart from your competitors.

• But ensure that you make memes only when it matches your niche/target audience (youngsters).

• You can also use memes to crack in-jokes about your industry. Through these, you can create a community around your brand and increase your brand awareness and image.

Presentation

• You can make presentations and share them online on various websites like SlideShare, etc. 

• These are similar to how Quora works in promoting your brand.

• Presentations are similar to infographics but the main difference between these two is: Presentations are multi-paged while infographics are single-paged content.

• However, you can use images, texts, infographics, and even videos in your presentation.

• Use presentations when you cannot accommodate all your information through infographics.

• However, keep your presentation’s borders, fonts, colours, styles, etc, consistent.

Screenshots

• Use screenshots to show your services/functions with a direct perspective. 

• Sometimes you can use your screenshots with your marketing copy as testimonials/customer reviews, to boost your company’s goodwill and brand.

• Many companies, especially on social media, share screenshots of their customer reviews to boost the confidence people have in their brand.

• Screenshots also provide visual verification of your products/services to your audiences.

• Use screenshots to draw attention to a particular part of the image.

• These screenshots can be added to your presentations too.

Types of Video Content for Content Library

No matter what your text/audio/image conveys, a content conveyed through a video is more effective, attractive and interesting/engaging. Use videos to educate your audiences/customers, make them understand your brand and move them to buying/availing your products and services, respectively.

You can post videos on social media platforms, websites, or on any presentations, etc. However, it is important to design videos according to your target audience. First make videos that will grab your target audience’s attention to your brand, then post videos to keep them engaged, later make videos that will convert your potential customers to actual customers, and finally post videos to maintain your existing customers.

Videos for Awareness Stage

BRAND FILMS

Enlist your company’s vision, mission, values, and core. Use sounds, visuals and involve storytelling to convey your content in an engaging manner.

ANIMATION VIDEOS

These videos provide visual and emotional stimulation which will attract many viewers. Keep it very creative, short, fun, and quirky. This will boost your brand’s creativity and thus, its image.

EDUCATIONAL VIDEOS

Convey new information related to your industry/business as educational videos to offer value to your audience’s everyday lives, thus leading to brand awareness.

VIDEO DOCUMENTARIES

These are similar to educational videos as they teach their audiences some real, valuable and new information too. It’s placed between brand films and educational videos. However, these are conveyed with style and in a story-driven manner.

EXPLAINER/TUTORIAL VIDEOS

These videos show a customer the ways to do something effectively. You can use these videos to produce ‘how to’, ‘what for’ , and other related content (relating to your brand/industry). It can also be funny or keep it engaging.

360-degree EXPERIENCE VIDEOS

If you want to share stories, places, or any related content to your brand/brand’s functions in an immersive and attractive manner, use this video type. If used in e-commerce, it is very useful. Eg: covering Fashion shows, etc.

Videos for Consideration Stage

After getting your audience’s attention towards you, now get to know them, their interests, wants trends, etc.

VIDEO EMAILS

Similar to email marketing. You send video ads/content about your brand/to promote it via emails. Always include call-to-action in these videos as you need to try to make your audience convert into your actual customers.

PRODUCT VIDEOS

Do a video to show a demo of how your product/service works to provide visual proofs to your audiences. This will help build brand trust.

COMPANY CULTURE VIDEOS

These videos will help the audience understand the culture you have in your company. These videos focus on the human-side of your company and lets you connect on an emotional level with your viewers/customers. Eg: Employee interviews, bloopers, etc.

TESTIMONIALS

These videos not only build brand trust and credibility but can also be used for showcasing the features of your products/services. Record these testimonials after a new launch/in-store events, etc.

Videos for Decision Stage

This is the stage where your potential customers will either choose to become your actual customers or not become one. Therefore, act carefully.

FAQ VIDEOS

At this point, your potential customers will be having some questions in mind, regarding your brand/product/service. To solve all their unsaid queries, you can make these FAQ videos and provide them a detailed and clear insight into what your company is all about. You can also have FAQ games as Mcdonald did.

DEMONSTRATION VIDEOS

Make these videos to give assurance to your customers that even after they have bought your products, you will still assist them in case of any doubts. 

PERSONALISED VIDEOS

Make videos with a personal touch and make sure those videos bring you happiness. Also, make your audience feel special after seeing the video. Eg: Cadbury Dairy Milk’s ads.

While you have finally converted your potential customers to actual customers, you need to still continue your customer marketing efforts to sustain your customer count.

THANK YOU VIDEOS

Such videos will make your audience appreciate the attention you have given to all of their efforts and work. These videos can also include employees thanking another employee. 

On the whole, make sure your video contents:

• Fit into a wider strategy
• Should adhere to your brand’s tone and all the content you want to communicate/promote.
• Should be distributed right (right time and right place, through right channels), for better results.

The Different File Formats for Content Library

There are various types of files that carry and share content. Out of the many, the basic four types are text, image, audio, and video. These files have different computer formats used with similar yet varying features, for different purposes. 

Audio File Formats

The basic extensions and their formats are:

.aif

AIFF (Audio Interchange File Format) audio file extension used for storing and sharing sampled sounds like rhythm, speech, sounds, etc. 

.cda

CD audio track file. It is only a shortcut to the audio file present in a CD and does not store any data in it. 

.mid or .midi

MIDI (Musical Instrument Digital Interface) audio file. It is only a protocol that allows computers/musical instruments/any hardware to communicate. 

.mp3

MP3 audio file. It is the standard format for any audio file. It usually compresses the size of an audio file into a very small file. The quality of the original sound will be preserved.

.mpa

MPEG-2 audio file. It also compresses the size of the original audio file using MPEG-2. Basic cassettes used MPEG-1. 

.ogg

Ogg Vorbis audio file. It is used by the users to stream high-quality digital multimedia files like audio, video, texts (subtitles), and also metadata, and also alter them. 

.wav

WAV (Waveform Audio File Format) file. It is either WAV/WAVE. Use this for uncompromised audio quality as they do not compress/loosen the audio files from the CD. This file format is used for radio, DVD, and TV, mostly. You can also use these audio files for web animations.

.wma

WMA (Windows Media Audio) audio file. It is a file extension of the Windows Media Player. It is seen as a competition to MP3 and other audio formats. However, it is both an audio format and a codec.

.wpl

Windows Media Player playlist. It is used to keep/maintain many video and audio collections/playlists in Microsoft Windows Media Player (9-12 versions).

Compressed File Extensions

.7z

7-Zip compressed file. Deals with archived files. They compress only the size, not the quality of the content. 

.arj

ARJ compressed file. Used by ARJ (Archived by Robert Jung) archiver. This format supports/allows long filenames, data integrity protection, large volumes of archives, and file version management. 

.deb

Debian software package file. It is available in Linux operating systems where you can use it to install, build, remove and manage .deb packages. These packages cannot be automatically downloaded/installed. A separate command has to be used to download a local package. 

.pkg

Package file/text file that is needed for building an.SIS installer file through which you can install various Apps on devices with Symbian operating system (OS). Only Nokia uses OS.

.rar

RAR file. These refer to the compressed files created by the WinRAR archiver. You can also compress large file sets and these can be split into multi-volume archives (if needed). It is similar to .zip files. These need to be extracted.

.rpm

Red Hat Package Manager. These are used for installing software on Red Hat Linux or other Unix-like systems. 

.z

Z compressed file in any Unix-based systems, like Linux, etc. These were mostly used for backup purposes. However, now these can be opened in both WinZip (Windows) and Tar (Unix).

.zip

Zip compressed file. It is the commonly used compressed format. It is a single file that holds more compressed files. Even long files are supported. The main use for this is for emailing and sharing files over the internet. 

Email File Formats and Extensions

• .email – Outlook Express e-mail message file.
• .eml – Email message file from multiple email clients, including Gmail.
• .emlx – Apple Mail email file.
• .msg – Microsoft Outlook email message file.
• .oft – Microsoft Outlook email template file.
• .ost – Microsoft Outlook offline email storage file.
• .pst – Microsoft Outlook email storage file.
• .vcf – It specifies the format of a text file. These text files are used in bioinformatics, where they store gene sequence variations. In short, it is an E-mail contact file.

Font File Extensions

• .fnt – Windows font file
• .fon – Generic font file
• .otf – Open type font file
• .ttf – TrueType font file

Image File Formats and File Extensions

.ai

Adobe Illustrator file represents a single-age vector-based drawing. It is presented in either PDF/EPS formats. 

.bmp

Bitmap image used for creating bitmap graphics that seem real. When you take a photo or scan a document, you create bitmap graphics which is a collection of tiny parts called pixels. Different colors are used here. 

.gif

GIF/Graphic Interchange Format images. These are image file formats that are mostly used for online images. These have compressed images only but the quality of the image is not degraded. 

.ico

Icon file in Microsoft Windows. Icon file contains 1 or more small images at various sizes and colors, and they scale them appropriately.  

.jpeg or .jpg

JPEG image. It is the common format used by many cameras and photographic image capture devices. These also store and share photographic images on the world wide web/internet.

.png

PNG image. Portable Network Graphic (PNG) format of an image contains a bitmap compressed and a similar compression to that of a GIF file. These are mostly used for storing digital photographs, images with transparent backgrounds, and web graphics.

.ps

PostScript file. It is a file developed by Adobe and is mainly used by publishers for printing. These contain images and texts on the same page/together.

.psd

PSD image. It is used only in Adobe PhotoShop as PSD (Photoshop Document) is the default format for saving data in Adobe Photoshop. With this, you can work on a saved file again and again.

.svg

Scalable Vector Graphics file. It is based on XML. Using this file format, you can display different varieties of graphics on the Web and other platforms. These files have only simple plain text files that describe curves, lines, text, colors, and shapes. 

.tif or .tiff

TIFF image. These files use lossless compression where the quality of the image is maintained. TIFF fields can be saved in many color formats and in many forms. Mostly used by professional photographers. 

Internet Related File Extensions

.asp and .aspx

Active Server Page file. Used for telling the browser, which elements it needs to fetch from the server. These include texts, images, Javascripts, etc. Used by web servers who run Microsoft’s ASP.NET server-side web applications frameworks. 

.cfm

ColdFusion Markup file. It contains codes used for creating a web page by accessing a database. It is also used for creating reports as per requirements and also Flash forms. You can also use it with ColdFusion server and deliver web-based applications. Use ColdFusion 9 to open and edit CFM files.

.css – Cascading Style Sheet file. Used by web pages to store information in a neat and proper display format. These CSS files define font, style, size, color, spacing, borders, and the location of the HTML information on a web page. Use it to create a continuous look throughout various web pages of a website. While HTML is the structure, CSS defines its appearance and display.

.htm and .html

HTML file. The HyperText Markup Language file format is the basis of a web page. It uses tags to define headings, paragraphs, lists, links, quotes, images, and other interactive forms. 

.php

PHP Source Code file. It contains the Hypertext Preprocessor code/HTML embedded web scripting language. Mostly used as web page files to generate HTML from the PHP engine that runs on a web server, to create HTML content that is displayed on the web browser.  

.xhtml

XHTML file. It is an extension of HTML, developed to make it more flexible and extensible. It supports many data formats like XML etc.

Presentation File Formats

• .key – Keynote presentation
• .odp – OpenOffice Impress presentation file
• .pps – PowerPoint slide show
• .ppt – PowerPoint presentation
• .pptx – PowerPoint Open XML presentation.

All of these are used for infographic presentation of content. Each one is similar to each other, with only a few variations.

Spreadsheet File Formats and Extensions

.ods

OpenOffice Calc spreadsheet file. Used for collecting and joining data from various sources to work with/on the data. Here, the stored data are not passed back to the operational systems.

.xls

Microsoft Excel file. This format is known as Binary Interchange File Format (BIFF). You can use this to store Microsoft Excel documents.

.xlsm

Microsoft Excel file with macros. It has worksheets full of cells, arranged in both rows and columns. The cells are also embedded with a macros program using the Visual Basic for Applications (VBA) language. 

.xlsx

Microsoft Excel Open XML spreadsheet file. Used for storing data and creating mathematical models. Different mathematical applications are present here. This is the commonly used spreadsheet.

Video File Formats and Extensions

.3g2

3GPP2 multimedia file. These multimedia files are saved both in audio and video formats. Used for sharing this content online and for storing video files on mobile phones. 

.3gp

3GPP multimedia file. Mostly used by 3G mobile phones to support video recordings. However, these video files can be opened in 2G and 4G phones too. To open these files on your computer, you can use the VLC media player, Apple QuickTime Player, etc.

.avi

AVI file. It is only for Windows software. However, you can use it to have a synchronized audio-with-video playback. 

.flv

Adobe Flash file. Mainly used by web developers to integrate animations and other visuals into the websites. 

.h264

H.264 video file. This provides high-quality transmission of motion videos with a lesser bandwidth, just like MPEG-2. 

.m4v

Apple MP4 video file. It is similar to MP4 but this is supported only on iOS and is sometimes protected by DRM copy protection, unlike MP4. You can also encode video files in the iTunes store. It carries both audio and video.

.mkv

Matroska Multimedia Container. Used mostly for playing video and storing multimedia content (video with subtitles and audio). 

.mov

Apple QuickTime movie file. It is supported in Windows and Macintosh platforms too. This file holds many tracks of different types of media data. Mostly used for storing/saving video files and movies. 

.mp4

MPEG4 video file used for downloading and streaming videos from the internet. It can also store both audio and video files, subtitles, and still images. It’s a versatile video format which is also a standard one.

.mpg or .mpeg

MPEG video file. It is a popular format for movies distributed online/over the internet. They also compress the video files to make its streaming and downloading faster than other video formats.

.swf

Shockwave flash file. It is an Adobe product used for multimedia, vector graphics, and ActionScripts. It also contains animations with different degrees of interactivity and functions.

.vob

DVD Video Object used for playing video from a DVD disc. It supports digital video and audio, and also subtitles. This contains MPEG-1 Part 2.

.wmv

Windows Media Video file compressed with 1 or more video compression formats of Microsoft. Primarily used in Windows for storing videos and in other programs for making short animations.

Text File Formats and Extensions

.doc and .docx

Microsoft Word file. DOC files – used by Microsoft Word 2003 and the earlier versions. DOCX files are quite advanced as they use Open XML as their file format, which stores a document as a collection of separate files and folders in a compressed manner. For compression, it uses .zip. DOCX is used by Microsoft Word 2007 and later. 

.odt

OpenOffice Writer document file. It is similar to that of a Word document. ODT files are also supported by other OpenOffice programs like KWord (Unix0, NeoOffice (Mac), and AbiWord (Mac and Windows).

.pdf

PDF (Portable Document Format) file. These are usually read-only documents and they only preserve the layout of a page. Documents like eBooks, application forms, manuals, scanned documents, etc are all present in PDF format.

.rtf

Rich Text Format used by Word and Microsoft products/software/Office. RTF files development support cross-platform document interchange and the use of Microsoft products. Almost all the word processors support RTF files.  

.tex

A LaTeX source document file, which is also a high-quality typesetting system. Used commonly in electrical engineering, computer science, economics, statistics, and physics for processing the data of books, articles, and other publications.

.txt

Plain text file used for storing information in plain text with no advanced formattings apart from the basic fonts and font styles. Mostly used for taking notes, recording directions, even the codings of HTML are entered on NotePad. 

.wpd

WordPerfect document. Mostly contains formatted text and used for storing objects like graphs, tables, images drafted from other applications. 

Conclusion

These are the basics of building and maintaining your content library. Note that your must constantly update your content library to obtain optimal results.