Frames are controlled by a master document known as a frameset. The frameset document is not displayed in the browser in and of itself, but it sets up all the controls for the resulting page.
Along with the frameset document, you need at least two HTML documents of content. These are displayed in the framed areas created by the frameset (see Figure 6-1).
Figure 6-1. A framed page example.
Of course, within your frameset, you can create as many frames as you desire. For each of those frames, however, you need to have a corresponding HTML content page.
As you can see, the number of documents required for a complex framed site can begin to add upwhich as mentioned, causes extra demand on your server resources and your user's system resources, not to mention all the extra management issues that documents demand.updated