This graphic represents how the internet actually works. Using the metaphor of the ocean, search engines like Google are just skimming the surface and lead you to tidbits like Wikipedia, blogs, social media, news, shopping sites, etc. Library databases (where you find academic journals and scholarly peer-reviewed articles) are deep below the surface of the web, much deeper than what Google and other search engines can find. That's because library databases live behind something called a pay-wall and contain information that isn't indexed by search engines like Google. The information available to you is endless, but you need to know where and how to find it. Each number on this graphic has corresponding text from CNN Money (link underneath the graphic). It is quoted in part here:
1. Google & Bing Search Engines (boats on the surface): To produce results, major search engines scour the Web. They follow links to index sites. That's like dragging a net across the surface of the ocean.
2. Wikipedia, News, Amazon, Linkedin, Blogs, Twitter (fish just underneath the water's surface being caught by Google and Bing): These nets capture less than 1% of Web content. They totally miss the data behemoths.
3. Databases (whale deep in the water): Ask a database a question, and it generates a unique page. These don't get surfaced to the indexable Web.
4. Academic Journals (another whale even deeper in the water): Also hidden are standalone pages and documents behind private networks, like academic journal articles.
5. Tor Network (octopus on bottom of ocean): The most hidden section of the Web is Tor. You can only get inside with special software that makes your location anonymous.
Image by Jose Pagliery & Tal Yellin/CNN Money from "What is the Deep Web?" https://money.cnn.com/infographic/technology/what-is-the-deep-web/
This video describes what top level domains are and what they mean. Top level domains are the .com, .org., .edu (etc) part of a website. This can tell you a lot about the information being shared and by whom. But there is an assumption that a .org website is more credible than a .com website -- that's just not true because anyone can purchase or sign up for a .com or .org. You need to evaluate all the information you come across and make no assumptions about trustworthiness until you've done the work. Check out the evaluation techniques on this research guide (especially the SIFT and CRAAP methods) for help with evaluating websites.
Top-Level Domains from Imagine Easy Solutions on Vimeo.