The 'Users', 'Groups', and 'Convert' menus.
Common shortcuts to functions you do in the user manager. You also have buttons for these actions, and can right click on users for these actions.
Common shortcuts for groups. You can also right click on users and get these same options.
The migrate user's data folders option will go through all the users and update references in their VFS from one value to another. This can be useful when you have changed hard drive names, paths, OS running CrushFTP, etc.
Conversion options to 'normalize' all the user.xml values. This is essentially the conversion from older CrushFTP versions. Any entries in the user.xml file for a user that match the default user's user.xml file will be removed so that the setting is inherited. Technically you could use this feature at any time, but usually you only need it after upgrading to CrushFTP6.