Frames
Frames were introduced in 1995 as a way to split the web page into multiple active windows. It also allowed for faster loading because only one part of the web page had to load when the rest stayed static. They are now being used less and being phased out mostly because of accessibility issues and newer technology that allows for fast loading.
The large window frame chages as
you click the links on the left frame.
HTML frames allow authors to present documents in multiple views, which may be independent windows or subwindows. Multiple views offer designers a way to keep certain information visible, while other views are scrolled or replaced. For example, within the same window, one frame might display a static banner, a second a navigation menu, and a third the main document that can be scrolled through or replaced by navigating in the second frame.
An HTML document that describes frame layout (called a frameset document) has a different makeup than an HTML document without frames. A standard document has one HEAD section and one BODY. A frameset document has a HEAD, and a FRAMESET in place of the BODY.
The FRAMESET section of a document specifies the layout of views in the main user agent window. In addition, the FRAMESET section can contain a NOFRAMES element to provide alternate content for user agents that do not support frames or are configured not to display frames.