Locomotion is the concept of travel, legs, tracks and wheels are forms of locomotion. Legs are the hardest to perfect, tracks are not agile but can go over rough terrain better than wheels, wheels are more agile but can’t go over rough terrain.
There are also forms of steering they are the following; dynamic, car-type, tricycle and omnidirectional. Dynamic is where you have a circle and you put three wheels on it in a triangle formation where the wheels spin but not. Car-type is exactly what it sounds like it is where you have four wheels two wheels swivel and the others turn. Tricycle is exactly like car-type but you have three wheels instead of four. Omnidirectional is where all of the wheels swivel by themselves, each wheel has different motors that let them swivel so to do a burn out the left wheel could be facing right vise versa.
Most robots are very similar but they all have their differences.