What do Physics Materials define in Unity?

Physics Materials in Unity are specifically designed to influence how colliders interact with each other during collisions. They provide properties that dictate the physical behavior of GameObjects when they come into contact, such as friction and bounciness.

By assigning a Physics Material to a collider, you can modify how that GameObject behaves upon collision. For instance, a material with high friction will cause objects to stick together when they collide, while a material with low friction will allow them to slide past each other more easily. Similarly, the bounciness property determines how much energy is conserved in a collision, affecting how high an object might bounce off a surface.

This aspect is crucial for creating realistic physics interactions in games, helping to provide players with an immersive experience where objects react in believable ways.