Frames can be a useful addition to any web site. They allow you to display 2 or more web pages in a controlled fashion in one browser window.
For example you could use frames to have a consistent menu in one frame allowing you to link to several pages in the adjacent frame Frames have long been a source of debate in terms of good web design.
If that doesn't make much sense consider the example below (or to see in flesh click link above to see this page as a frame)
This page is made up of 3 webpages. You have the the header page, the side menu page and the main area page. The advantage with frames is that you could create a link within any of these 3 frames that would change the main area frame
thereby giving consistency to your page with menu and header
Frames are not universally popular. Whilst the vast bulk of surfers are indifferent, there are 2 vocal, (very) minority camps with opposing views. Several criticisms cann be laid at the doors of frames. Firstly frames can suffer badly from screen resolution. Secondly not all browsers support them. Frames can be a nightmare to create links in. Remember each page making up a frame set needs to load in (hence can mean lengthy download times). Finally often can create horrible looking pages (as their oppostion frequently point out).
to see frame version of this page
Select one of these 2 links
learn more about frames and how to link within frames
how to create frames with HTML