After 3 years of playing this game, can someone enlighten me with the meaning of "Ranked Divsion"?

I'm saying these "Urgot's Butthole" type of random groups that Riot put a certain amount of people in. Do they have any actual meaning or impact on the Ranked system? Like am I more likely or less likely to queue against or together with the same people in my division?? Or they are simply useless and just to prevent me to see all the other players on the ladder so I have to go to a third party website to check my actual ladder status?