How do you get ratings in chess?

Answer 1

If you play against somebody in a rated game, the result determines how many points you win or lose after the game. The winner gains at least one point on his or her rating, while the loser loses at least one point. If the game is draw, sometimes a point or so is given to the weaker player if he/she manages to survive his/her opponent to the draw, while his/her opponent might lose a few from his/her rating.

The higher the rating, the stronger the player is. Typical grandmasters or World Champions have ratings of at least 2200.