Guild is a group that people can meet other players. It is maximum of 50 people. You can get fame everytime you finished a game, if you play with your guild players you can get more fame than play with yourself. Fame can gain your guild levels if you have higher level you can get better rewards. The highest level is 100.
Team is similar with guild but the maximum player is 6 people. The level of team is same as rank tier. You cannot get any rewards from team.