At the end of a WOD you'll see various ways of coping with the intensity and exertion found in the workout. Some collapse on the ground, some sit on the closest object they can find, and very few are left standing. Intensity is "where the good stuff happens", according to Coach Greg Glassman, founder of CrossFit. A workout is just a workout, but an intense workout is where you can have a significant impact on your body's metabolism and overall health and fitness. Ramp up the intensity and the results have to follow.
Recovery after a hard WOD requires a period to just rest to a point where you can function normally again. Following this, it's important to utilize some of the mobility tools and stretching we practice daily. Finally, recovery requires good nutrition and sleep. Do this and every time you hit it hard in the gym your performance will improve.