Title tag - definition
The title tag is an HTML element of a web page that describes the content of the page.
The title tag is one of the primary elements that search engine crawlers look at when evaluating that page’s relevance to a particular search term and when indexing pages.
The title tag does not appear on the web page itself, but users will see the title tag at the top of most browsers when on a particular page. The title tag is also the text that is displayed as the headline in the search engine results.