Static body
A physics body that never moves — infinite mass, zero velocity — meant for floors, walls and other immovable level geometry.
Physics engines sort bodies into three kinds. Dynamic bodies are driven by forces and collisions. Kinematic bodies are moved by code but ignore forces. Static bodies hold perfectly still: they are never integrated forward, and the broad phase can treat them specially because their position does not change between frames.
The distinction is performance, not just bookkeeping. A level may hold thousands of static colliders — the whole map's geometry — and the engine skips integrating every one of them each step. Dynamic bodies collide against them as against an infinitely heavy wall. Box2D calls them b2_staticBody; Godot has a StaticBody node. Moving a static body at runtime usually earns a warning — many engines rebuild spatial structures for it, and that is expensive.