Major League Soccer (MLS) is a men's professional soccer league sanctioned by the United States Soccer Federation. It represents the sport's highest level in the United States. The league comprises 29 teams: 26 in the United States and 3 in Canada. Its headquarters are in Midtown Manhattan.
The MLS regular season typically starts in late February or early March and runs through mid-October, with each team playing 34 games; the team with the best record is awarded the Supporters' Shield. Eighteen teams compete in the postseason MLS Cup Playoffs in late October and November, culminating in the league's championship game, the MLS Cup.
Instead of operating as an association of independently owned clubs, MLS is a single entity in which each team is owned by the league and individually operated by the league's investors. The league has a fixed membership like most sports leagues in the United States and Canada, which makes it one of the few soccer leagues that does not use a promotion and relegation process. Wikipedia