For this tutorial to work propelly first make a room whatever. Yo can use my previous tutorial for making a room
Props that dont move.
The entity name is called a prop_static and do not move anywhere if shot or if the grav gun is used on them.
Props that do move.
The entity name is called prop_physic and you are able to move around an shoot.
Props that work with other entitys.
The prop name is prop_dynamic and it is able to work with other entitys in animations and such.