Difference between .state and 'url'

I’m new to ionic (and AngularJS), and I’m trying to understand some things. For example the stateprovider/routing thing. I’ve downloaded the ‘sidemenu’ template to start with. In app.js under .config, the different states are listed out, but I don’t seem to understand the function of the ‘url’ in all of them. If I understand correctly, the state is similar to what can be found in the href items (in menu.html for example). Take the Browser item > href="#/app/browse", so the state must be app.browse (?). I don’t see why /app is added in there, but ok.
Then the ‘url’ part, according to this site, is the URL route that can be accessed via href properties. But isn’t that what state already does?

Then my second question: I don’t understand that at the opening of the app, the ‘playlists’ page appears straight away. In .config it does say $urlRouterProvider.otherwise(’/app/playlists’), but if that were the case, then why isn’t it just the playlists html page that shows instead of BOTH the sidemenu template AND the playlists page? I thought the .otherwise was only triggered if no state was ‘chosen’, but apparently the first state (app) was chosen with menu.html as templateurl, so why also the playlists state?

I hope someone can help me clarify some things :stuck_out_tongue: . Thanks in advance.