Collision2DNamespace: UnityEngine

collider	The incoming Collider2D involved in the collision.
contacts	The specific points of contact with the incoming Collider2D.
gameObject	The incoming GameObject involved in the collision.
relativeVelocity	The relative linear velocity of the two colliding objects (Read Only).
rigidbody	The incoming Rigidbody2D involved in the collision.
transform	The Transform of the incoming object involved in the collision.

Collision2D