I recently saw a diagram that explained it well. Both a team and a clique are focused on a goal, but the goals are different. A clique has an inward focus and a team has an outward one.
The irony is that a team, being united together in an outward goal, has a much healthier community factor than those who are only focused on themselves – and they accomplish something in the process. A group of people focused only on themselves grow discontented in a variety of ways, which has direct impact on their effectiveness.
The strength of the team lies in the goal. The most gifted team in the world flounders without a clear goal. Likewise, even a team of average people can accomplish amazing things with a vision in place and a goal in front of them.