They're parts of the lever. Different people use different names.
Lever is what you press with your hands to close the clamp.
The thrust washer is what's between the lever and the surface clamped to.
When I said cam, I think I used the wrong word, as it's the word that describes the type of clamp. When I said cam, I meant the pin that goes into the lever that connects with the bolt.
The bolt is the part with the threads that passes through the surface to the other side where the nut threads on to.