CrossFit is a strength and conditioning program which optimizes fitness through constantly varied , functional movements performed at relatively high intensity. Does that sound complicated? If so watch the videos in the links.
CrossFit is also the community that spontaneously arises when people do these workouts together. In fact, the communal aspect of CrossFit is a key component of why it’s so effective.
CrossFit defines fitness in a meaningful, measurable way - increased work capacity across broad time and modal domains. This may sound like a foreign language but just come by and give it a try and it will all make sense.
(above links courtesy of CrossFit Inc.)