In 1998, two graduate students at Stanford University, Larry Page and Sergey Brin, developed "Backrub", a search engine that relied on a mathematical algorithm to rate the prominence of web pages. The number calculated by the algorithm, PageRank, is a function of the quantity and strength of inbound links.[22] PageRank estimates the likelihood that a given page will be reached by a web user who randomly surfs the web, and follows links from one page to another. In effect, this means that some links are stronger than others, as a higher PageRank page is more likely to be reached by the random web surfer.
Simply put, search engine optimization (SEO) is the process of optimizing the content, technical set-up, and reach of your website so that your pages appear at the top of a search engine result for a specific set of keyword terms. Ultimately, the goal is to attract visitors to your website when they search for products, services, or information related to your business.

Social sharing and comments: If you're on social media, you're probably familiar with sharing and commenting. Social shares and comments are good indicators of how relevant your content is with your target audience. If a viewer watches your video and takes the time to share it with their network, you probably created a great piece of content. Social shares are also important because the more times your video is shared, the more it'll be viewed. If your goal is to reach to reach a lot of people, social shares is good metric to track.