What is the difference between A Pre Amp and A Amplifier?

Question

What is the difference between A Pre Amp and A Amplifier?

Answer 1

A preamp manages your sources, such as a cassette deck, CD player, turntable, and so on.  It allows you to switch between your sources and adjusts the line level of these sources to vary the volume of sound and can also allow you to alter the sound via equalization or through the use of simple tone controls (treble, bass). A preamp does not have a power amplifier circuit.

An amplifier, or a power amp, is a device which takes the output from the preamp and amplifies it to drive a set of loudspeakers.

There are also two types of devices which have the pre-amp and power amp elements built into one unit: the receiver and the integrated amplifier.

An integrated amp is named as such because it integrates both the preamp and the power amp into one unit.  

A receiver is the same as an integrated amp but with a radio tuner also added into the unit as well.