What is the difference between Ranked and League mode?

I just got Splatoon 2 and it is very fun! I'm very interested in the ranked and league modes, can someone explain to me what the difference between these two modes?

The definition from Inkpedia:

League Battle is a multiplayer mode in Splatoon 2. It replaces Splatoon's Squad Battles as an option for co-operative ranked play. In a two hour period, players team up in a group of two or four and compete with other groups to earn as many points as possible. At the end of a two hour period, results will be shown in a ranking

While in ranked mode you can change your rank by playing and are not able to play with friends, but in league mode you can play with friends but not change your rank