Depending on whether they involve contact between objects or bodies, forces are separated into two groups : contact forces and non-contact forces.
Contact forces are forces that involve the actions (push or pull) of one object in direct contact with another examples include a foot hitting the ground, a bat striking a ball or players colliding into each other. Non-contact forces involve no contact between objects. The most common nort-contact force is gravity. Weight is also a non-contact force.