Is an exercises where there is no range of motion happening yet the muscle is still engaged. Example: Holding a seated squat for thirty seconds or a plank for thirty seconds is an Isometric exercise. There is no other motion other than holding a position in place. This is a great way to strengthen the muscle and work more on the muscular endurance.
Lifting objects at consistent speeds is considered an Isotonic exercises. For example: Bicep curls is an Isotonic exercise. There are 2 motions that Isotonic exercise consist of, Concentric and Eccentric. Concentric motion is when the muscle is contracted and shortened. Example: Flexing your bicep is concentric motion. An Eccentric motion is when the muscle is fully extended. Example releasing a bicep curl to complete the repetition.
Simply is a high intensity exercise that demands quick bursts of stamina for shorter periods of time. For example: 100 meter sprint, is an Anaerobic exercise.
Is a prolonged period of training that tones out the body and builds heart and lung endurance by putting the body through a longer sustained exercise. Example: swimming, biking, jogging and dancing are all examples of Aerobic exercises.
These are 4 different systems you can think about working when at the gym.Of course you can create a combinations of different systems in one session. For example: Doing a circuit with weighted squats, push ups and sprints is working both the Isometric and Aerobic systems.
Have a good training!