Havok is a professional physics engine used in 500+ shipped games and VR experiences. It simulates rigid body dynamics—how objects fall, collide, slide, and rotate. Havok handles collisions, constraints (joints), impulses, and solver iterations to create realistic physical interactions. Unlike in-engine physics (Unity's PhysX, Unreal's Chaos), Havok is a standalone engine optimized for stability and performance across multiple platforms (PC, console, VR).