Frames are a structuring tool in html. Modern websites have phased out their general use but older sites may still have them. Here is an example of a page that has been set up in frames:
The code for this can be found here. Download and then unzip the folder to view it. How are frames accomplished? Then experiment with your own frames set up. Try to make a menu of at least 3 choices on the left-hand side and have their links appear on the right.