If we bring these two parts together, as they really are in the point-contact transistor circuit, both lamps will shine. This is because the left, forward biased, part of the circuit introduces enough holes to be able to activate the right part as well. So with the transistor you are able to control and influence one part of the circuit, the right part, with the aid of the other, the left part.

The three electrodes of the transistor have different names. Connected to the metal base is the contact simply called the base-electrode. The gold contact where the current enters (left) is called the emitter-electrode and the other gold contact (right) is called the collector-electrode.