Search engine optimization (SEO) is the process of improving a website's visibility in free search results. A brand's website is often filled with helpful content, based on the words and phrases users use in searching for its products or services.
Search engines like Google and Bing use bots to crawl web pages, collecting information about each page and adding it to their indexes. An index serves as a huge library where a librarian can locate a particular book (or in our case web page) based on what one is looking for at any given time. After that, algorithms analyze pages in the index based on hundreds of ranking criteria or signals to determine which pages are listed in the search results for a particular query.