An amplifier or amp, as it relates to the car audio hobby, is a piece of hardware
the boosts an audio signal. Typically the audio signal will enter as a pair of RCA wires from a CD player or computer. The amp then boosts the signal and sends it out to each individual speaker thru standard speaker wire; one positive and one negative. An amplifier usually takes lower voltage AC input from the RCAs and amplifies it to send out high voltage AC signals to the speakers.
Picking an Amplifier
Setting Your Gains
Bridging An Amplifier