What is SEO Indexing?

After search engines have crawled a website, they will store the content in an index to be displayed in search results. The index entry shows the content and the URL of the page. An index is essentially a database of all that has been crawled on the web. Similar to an index in a book that provides readers with a roadmap of the information contained in the text, a search engine index stores data from billions of web pages, which can be retrieved quickly whenever a user searches for something.

Just because a page gets crawled and indexed doesn’t mean the content stays in the index forever. URLs can be removed from the index for a variety of reasons. The page may have been blocked from being crawled or penalized for violating search engine guidelines. It makes sense that if you move or delete a page, it will be removed from the index.

You can give Google instructions on how to index your website. Meta tags are added to the HTML to let the bot know whether to index a page or not. For instance, the “noindex” tag tells the search engine not to index it, but the content can still be accessed by users on your site. The “nofollow” tag is often used in tandem with “noindex” to let bots know not to follow the links on the page to other pages. Also, the “noarchive” tag stops search engines from creating an archive or a cached copy of the page. A cached link displays what a page looked like when the Google bot last visited it, which means the content may be outdated if changes were recently made to the site.