Jogging is a form of trotting or running at a slow or leisurely pace.
The main intention is to increase fitness without stress.
Jogging is a "high-impact" exercise that places strain on the body, notably the joints of the knee.
This is actually one of the basic reasons for doing the exercise, as the impact drives growth processes in the areas of the body stressed by that impact.
Some people drop jogging in order to take up "lower-impact" exercises such as stair climbing, swimming or cycling.
Jogging is often used by serious runners as a means of active recovery during interval training.
The runner who may just have completed a fast 400 metre repetition at a sub-5-minute mile pace, may drop to an 8-minute mile pace for a recovery lap.