Explain the difference between a joint's possible range of motion and its actual range of motion.

Each kind of joint exhibits a probable range of motion related to it. This conceivable range of motion relies upon the kind of joint it is, rather than the features of the person who exhibits this joint. However, the actual range of motion of the joint relies upon the fitness levels of the person.  

As the possible range of motion is the speculative highest range of motion, the actual range of motion will always be less.  

because health skills are tools and strategies and also practical skills are also something you need to learn (like tools and strategies) and put it in reality.