what is the difference between a sport and a game
In a sport, the athlete can take independent decisions, but a player cannot take such independent decisions in a game. A decision is taken at a game collectively among two or more players. Another difference between sport and game is that the former is based on physical energy and the later is based on mental strength. Sport is played with a view of competition in mind while game is played with a friendly attitude.
First of all let me address the difference between Games and Sports (because they are of somewhat similar nature). Sport is about physical energy while a game may involve physical energy as well as mental strength.