the push-up is one of the most well-known and performed exercises out there that has been with us for centuries, but still, there are mistakes that people make and variations that can totally change the normal challenge level of the conventional push-up.
these variations mainly come from the changes to the main variables of this exercise, which some are: feet position, hip position, level of protraction/retraction of the shoulder, angle of the body compared to the ground, the distance the hands have with each other, level of the shoulder internal/external rotation, level of shoulder abduction/adduction, level of shoulder extension/flexion, whether the knees are bent or not. if you bend the knees, it is alright and you still can perform the exercise but in some variations like the conventional push-up, it is going to make the exercise easier by reducing the range of motion. keep in mind that you can mix these variables and they might affect you slightly differently compared to what has been said in this video. these examples are given mainly based on the conventional push-up.