An AND gate can have two or more inputs. The output of an AND gate is true when all its inputs are true.
Light Emitting Diode A transducer which converts electrical energy to light. Usually abbreviated to LED.
Transistor NPN A transistor amplifies current and can be used with other components to make an amplifier or switching circuit. This symbol is for a bipolar junction transistor (BJT), the type you are most likely to use at first.
Galvanometer A very sensitive meter used to measure tiny currents, usually 1mA or less.