What is Title Tag?

A snippet of code that gives a webpage a title. It helps build context and demonstrate site relevancy, and in less competitive niches, having the right keyword in the title tag alone can move a page to the top of the SERP rankings.

From 12 Essential On-Page SEO Factors You Need To Know Ep. 541

An HTML element whose primary job is to tell visitors and search engines what they can expect from the web page in the shortest and most concise way possible. It appears in the browser tab and on the search engine result page.

From How to Craft the Perfect SEO Title Tag (Our 4-Step Process) by Joshua Hardwick #409

An HTML tag that labels a webpage; it should be unique per page, reflect that page's keywords, and stay within approximately 65 characters to avoid truncation.

From Optimal Title Tags for Internet Marketing, Ajax Sucks for SEO, When to Use a Splash Pages - Unknown Secrets of SEO E-Webstyle Number 19

An HTML element that names a webpage; placing target keywords in the title tag, especially as the first words, is one of the most important on-page ranking factors.

From Search Engine Visitor Optimization (SEVO) and Google Factors for SERPS - #seopodcast 43

An HTML element that names a web page; the hosts call it the single most important on-page SEO element and compare it to a newspaper headline, saying it must describe page content rather than just displaying a company name.

From The Worst SEO Mistake, Website Design Consistency and SEO - Unknown Secrets of SEO E-Webstyle Number 63