What actually Ionic.io() doing?

Hi all.
I am using this example from ionic docs

`// kick off the platform web client
Ionic.io();

// this will give you a fresh user or the previously saved 'current user’
var user = Ionic.User.current();

`

all works fine. But i am not understand what exactly this line Ionic.io(); doing. I am trying run code with or without this line… any difference