Overwatch is an incredibly complex game but it doe not appear so at face value. All kinds of different people from around the world play this game and there have been hundreds of thousands of strategies made and hundreds of thousands of players play the game to its highest potential. This game has a competitive mode that holds 98% of the player base of 10 million. SR is the Skill Rating of a plyer and ranges from 1 - 4000+ and then a percentage of players belong to each rank, Bronze being the lowest and top 500 being the higest.
There are 26 playable characters in the game who lie under one of three categories. Damage, Tank, or support, each of which does exactly what the name entails and each team consists with 6 players receiving 2 of each role. Damage characters do damage, tanks tank damage, and supports support a team by healing