Understanding the Edit, Clear, and Create Webpage buttons
The Edit button allows you to manually and directly edit the link created by the link wizard. Clicking this button opens a dialogue box that prompts you to enter a URL for the menu item. If the URL has already been entered, either through the link wizard or directly via the Edit button, it will appear in the field and can be erased if you'd like to change it.
The Clear button removes the link that is currently set for the menu item. This button is most useful if you're creating a menu item with no link, such as a parent folder.
The Create Webpage button allows you automatically create a webpage with the same name as the menu item and create a link to it. For example, if you've created a menu item called Products, but haven't yet created the corresponding webpage, you can click this button and a webpage called Products will be created in the Web Pages module and automatically linked to the menu item. You can then edit the new webpage from the Web Pages module.
Note that if you are using the Create Webpage button, it is recommended that you keep the menu item hidden until you have added content and it is ready to be displayed on the live site.