They want to make sure the customer will not have problems getting around the website.
You would be looking at whether it is possible ot reach every page of the website from the home page via whatever route, and that your links all work! In a system that is not web based its a similar thing - you need to make sure the functionality is actually accessible at some point! Sometimes there is more than one way of reaching something, in which case you would be checking every available means of accessing that functionality.
It is not only verifying the navigation that method C gets you from point A to point B. It is also verifying that you can access all areas of the site (using your site map as a reference).
While testing navigation, I once tested a site and found that an area on the site map was not accessible at all! It had been coded - but there was no navigation available to access it!
So not only do you have to verify that all navigation takes the user to where they are supposed to go (or back to where they once were), but that there is navigation available to all of the areas that exist!
I also think that navigation testing has some overlap with usability testing.
I would hope that you should be able to find what you need with a minimum # of clicks. So what is this minimum? I forget where I picked this up from, but my rule of thumb is less than 4 clicks from the home page for most page views.
Page views that depend on some type of login start counting from the account login page.
I would think that navigational testing would not be specific to a web site. Would any application, be it C/S or desktop, have navigation in it that needs to be tested. Menus that open other areas of an app. In Photoshop for instance if you select View-->Show-->Color Palete (the path and names may not be exact but they should be close)it opens a window containing the Color Palete. Would this not be navigation testing?
I am just trying to keep things straight in my head. It is getting so cluttered in thier I am starting to trip over things.
Any hyperlink,gif icon or button that exists in a page is leading to the destination page or not.when end user clicks on buttons like submit cancel what are next pages that can be viewed will be included.
if it is a stand alone application we have to test for the menu options that exist in the form and the buttons that operate on each form and where user will be lead on a mouse click.these things should be tested in navigational testing.