hreflang is a technical solution for sites that have similar content in multiple languages. A site owner wants search engines to point people to the most “fitting” language. Say a user is Dutch, the page that ranks is English, but there’s also a Dutch version. You would want Google to show the Dutch page in the search results for that user. This is the type of problem hreflang was designed to solve.
in this (very long) article we’ll discuss: