The id is a unique identifier for that group. This can be used to get more data about a specific group.
The name is the name of the class or group eg. "VLE Admin", "9En-1" etc.
(whoops! this was meant to be a reply to Arnaud Delobelle's comment!)
It would be good to specify the object returned for each group: it seems to be an object with two attributes: "id" and "name". What do these represent?