A footer in the hypertext markup language (HTML) is an element tag that defines the text or code inside the tag as belonging to the HTML footer section. Unlike a footer in word processing computer programs, an HTML footer does not automatically position the text at the bottom of a document or the display window. The primary purpose of using a footer tag in a document is to define the text that belongs to the foot section so it can be processed and positioned by other layout methods, such as cascading style sheets (CSS) or JavaScript®. An HTML footer can contain nearly any type of code or information, with the exception of a header tag.
For the most part, an HTML footer behaves just like any other standard tag, despite the fact that the name of the tag implies positioning information. Wherever the footer is located within an HTML document is exactly where it will be rendered when the page is viewed. Additionally, an HTML document can have as many footer tags as desired without restriction. The way a footer is rendered is similar to any other HTML text, including positioning in table cells and other formatting elements.
Similarly, like other tags, an HTML footer can contain almost any information or code required, with one exception. An HTML footer cannot contain a header tag within its own block. Images, links and any other style elements can be used inside a footer without any restrictions. It should be noted that, when used in conjunction with advanced layout and positioning styles, it might be difficult to calculate exact dimensions from a complex footer.
The HTML footer tag helps to define a block of text or code that can be called on and formatted according to rules established in other standard web-based computer languages. Most notably, a CSS document can be used to capture a footer and ensure that it is consistently displayed at the bottom of the viewing window or document, either as a floating visual element or by defining a footer section. A similar effect can be achieved through the use of JavaScript®. This leaves the HTML footer tag as being primarily a way to define metadata in a document.
Although anything can be placed inside a footer in an HTML document, they are most often used to hold copyright information or notices. They also can be used to hold contact information such as an email address or phone number. Depending on the type of website, the footer also can be used to provide a consistent and simple navigation field to move between web pages.