Each region can reference a separate URL, allowing the display of multiple Web pages within one page. One frame can refer to another frame through its name, allowing one frame to be updated by clicking on a link in another. You should limit the total number of frames to three or four as each one usually requires a separate page to load within it. Frames open up new interface possibilities on the Web.
Table of contents can remain fixed in one frame while the content frame is updated.
Frames work well with JavaScript or VBScript, you can update multiple frames with one click, and create intricate, interactive interfaces. To allocate portions of the page you give the ROWS or COLS attribute a list of absolute or relative values each representing a frame. Multiple relative-sized frames get equal amounts of the remaining space. Example frameset with 3 rows, the first two a fixed height, and the remaining space allocated to the bottom frame. Note that in Netscape 3, the frame sizes still vary somewhat when resizing your window, while in Explorer 3 they don't.