Pilates is a gradual build up, a layering of understanding and strength, which is achieved over time. It is there to help you build on what you have to become the best you can be, and was not designed to be competitive, but rather therapeutic.
A great place to start learning Pilates is with the Matwork.
The STOTT Pilates Matwork is a repertoire of exercises made up of the Essential, Intermediate and Advanced Matwork.
Matwork is an opportunity to work the core (torso) muscles concentrically (the muscle developes tension whilst shortening to overcome resistance) and eccentrically (the muscles developes tension whilst lengthening to overcome resistance).
The basis of STOTT Pilates is the STOTT Pilates Five Basic Principles. These are taught at the beginning of your Pilates journey. These Basic Principles are extremely important, and are applied to every single exercise. Without these Principles you may as well just be moving your torso, arms and legs around aimlessly.
As the exercises are learned, the Matwork workouts are kept interesting by increasing the level and also by adding in various props.
Modifications are included in workouts to accommodate certain weaknesses, address specific injuries and body types, as well as to make an exercise more challenging.