In HTML, the title tag is an important tag found in the header of every page. The title tag is used to give a page a title, which is seem at the top of the browser, as well as in search results in search engines.
A well crafted and unique title tag is a key piece of SEO.
A notice that another website has linked to your website. A somewhat new web technology, trackbacks are an active way to announce a link, and a great way for web publishers to track who is linking to their articles.
Trackbacks are often associated with blogging, and blogging software which automatically supports trackback linking.