Pilates is different from most exercises because it's non-impact and safe, and it really works on using the body as a whole (uniformly developed). You may lie on your back, on your side or kneel on the floor. When you move the body, you're trying to move it from the "powerhouse", using your abdominal wall to protect your back. You're also working the body very evenly and symmetrically, making sure one side is not working harder than the other.
Pilates is an endless journey. It can be a wonderful journey but it never ends. In Pilates, we routinely practice our series of exercises, plus additional exercises we add to address specific needs. Often we finish our workout with invigorating exercises that challenge and inspire us on our journey. These are the mainstays of our Pilates practice.
Pilates is also compatible with all other forms of exercise. Pro athletes love it because it's a great way to keep their muscle tone without stressing their joints to the point of risk for injury and to increase their flexibility. Dancers love it because they get strong without losing their long, lean lines. Tennis and golf players benefit from the spine flexion and torque, and learning to use their arms from their center, resulting in less shoulder injuries/stress.