What does first mobile index mean?
 

What does first mobile index mean?

Google is rolling out a new mobile-first index. This means Google will create and rank its search listings based on the mobile version of content, even for listings that are shown to desktop users.

Google has started to use the mobile version of the web as their primary search engine index. A search engine index is a collection of pages/documents that the search engine has discovered, primarily through crawling the web through links. Google has crawled the web from a desktop browser point of view, and now Google is changing that to crawl the web from a mobile browser view.

In the current index, which most people will continue to get results from, desktop content is indexed and used for showing listings to both desktop and mobile users. A special mobile-friendly ranking system is then used to boost content for Google's mobile listings.