The teep is not a front kick in the sense that it’s not a strike. It’s not used to create damage but to push the opponent away from you, thus the push kick. Also it is not done with the ball of the foot but with the bottom of the foot. The foot jab is slightly different in that the hip is extended.
Also the teep isn't always for pushing opponent away from you but also to stop his advance. The teep only need to stop the opponent or knock his balance off slightly and set up for a counter (like a low kick).
