Objects in Unreal Engine have collision properties that can be modified to design the behavior of the object when it collides with another object.
In real life, collisions occur when two objects move and meet each other at a point of contact. Their individual object properties will determine what kind of collision we get, how they respond to the collision, and their path after the collision. This is what we try to achieve in the game world as well.
The following screenshot shows the collision properties available to an object in Unreal Engine 4:
If you are still confused about the concept of collision, imagine Static Mesh to give an object ...