The pages in your web site will be organised according to the usefulness of the information. The "Home" page is the one that is accessed first when anyone looks at your web site and will have the most important/up to date information. The remainder of the pages need to be arranged in some kind of order to assist the user in finding what he wants quickly and easily. In Bridgewebs this is the "Menu" that will be shown on each page of your web site. There are 2 levels, the Top level and Second level.
You can consider this like your Sunday Newspaper, you have the Front Page of your main Newspaper and then you have a number of pull-out supplements. The Front Page of the Newspaper usually has a list of the supplements (the Menu). In the case of the Web Site the supplements can consist of 1 page.