Voltage: Put simply, this is the force with which electrons are pushed around in an electrical circuit. Think of this like the pressure in a water hose. Measured in Volts (V). A higher Voltage will make a motor turn faster, or a light bulb burn brighter.
Amps: A measure of how much electricity is used, or is available to be used at any one time. Think of this like the size of a water hose. Measured in Amps (A). A higher Amperage will give a motor more torque and faster acceleration.
Watts: Amps multiplied by Volts gives you Watts; a measure of the work that electricity does per second.