HTML tag used to define the text in the top line of a Web browser, also used by many search engines as the title of search listings.
A title tag belongs in the <head> section of a Web page, above the <body> section. Technically, it may be above or below the META tags, but it is common practice to place the (very important) title tag above the (less important) meta tags.
The information contained in a title tag appears at the top of the Web browser when viewing a Web page, and at the top of (most) search listings.
Writing descriptive title tags is an important part of optimizing a site to rank well with the search engines (and get clicked by visitors). A well-crafted title tag can stand on its own without the benefit of the accompanying page content, as this is how it appears to Web searchers who know nothing about your site.
Include at least one targeted keyword or phrase, maybe more, instead of using all generic words that do not distinguish your page. If possible, keywords should be used early in the title to help search engines and visitors identify the main subject of the page, and also to avoid getting cut off by search engines that use relatively short titles. Search engines have limits as to how many characters are used from the title tag and
typically display between 50 to 70 characters.
see also: SEO Tools
Microcontent: How to Write Headlines, Page Titles, and Subject Lines
useit.com (September 1998)