The so-called active stretching means that the action is mainly kept in a specific position by the strength of muscle contraction, rather than other external forces, so active stretching is also called static-active stretching. The advantage of active stretching is that it can increase the flexibility of action and the strength of muscle contraction. For example, standing on one leg, lifting the other leg and keeping this posture still is a very standard active stretching.
It should be noted that the active stretching posture is difficult to maintain. Generally, it is difficult to maintain the active stretching posture to 15 seconds, so the general active stretching posture can be maintained to 10 seconds without too long.
The so-called passive stretching refers to using one's own weight or equipment to keep the limbs in a certain stretching posture. For example, lift your legs and then keep a certain posture with the help of your hands, or put them on the steps to keep a certain posture.
Passive stretching is a kind of slow relaxation stretching, which can also be expected to reduce the excitability of nerves and muscles. This is a good way to relax after exercise.