Update: Called once per frame. The frequency of Update calls depends on the frame rate, which can vary. Best used for operations that need to be checked or updated every frame, such as player input, animations, or non-physics-related logic. FixedUpdate: Called at a fixed interval, independent of the frame rate. The interval is determined by the physics timestep (default is 0.02 seconds or 50 times per second). Ideal for physics-related calculations and updates, such as applying forces to a Rigidbody, to ensure consistent and stable physics behavior.