In Unity, what component is required for a GameObject to interact with physics?

To enable a GameObject to interact with the physics system in Unity, it is essential to attach a Rigidbody component to it. The Rigidbody component allows the GameObject to be affected by forces, gravity, and other physical interactions. When this component is added, the GameObject can be controlled by the physics engine, enabling realistic movement and collision responses in a 3D environment.

Rigidbody acts as a bridge between the GameObject and the physics simulation provided by Unity. It enables features like applying forces, detecting collisions, and managing the GameObject's motion based on physical laws like mass, drag, and angular drag. Thus, incorporating a Rigidbody is fundamental when you want your GameObject to respond accurately to physical interactions, such as falling due to gravity or bouncing off surfaces in a game world.

While other components like Colliders are also necessary for detecting collisions, without a Rigidbody, the GameObject remains static and is not influenced by physics forces. Components such as Transform are crucial for determining the position, rotation, and scale of the GameObject but do not contribute to physics interactions directly. The Scene Manager, while important for managing overall scenes, does not facilitate physics interactions at the GameObject level.