I've always wondered what an amplifier was, as I've never owned one myself. I wasn't able to find any good descriptions on the search engines. What role does it play in a sound setup?

i'm pretty sure it's a portale speaker that amplifies sound of the instrament hooked up to it.

depends on what side of the production / performer fence you happen to be on.

most performance amps are simialar to what onop described where you have an amplifier and speaker combo packed into one unit and all you have to do is plug into the input jack and crank up the volume.

stereo / studio amps are slightly different in that they're generally sold as single amplification units that you'd run out to whatever speaker system / PA setup you have available.

both types of amps provide a stronger and clearer signal to the speakers. but depending on the specifics of what you're doing, and where, you can actually get away with not needing an amp. a high end amplifier usually has a built in EQ which also allows you to improve the sound signal to the speakers.

Oh alright. Cause a lot of people have amps in their home listening systems and I always wondered why they needed them, because on my speakers I can turn up the sound so loud that I can't listen to it comfortably. I didn't see the point of having the sound even louder. But you say it improves the quality of the sound as well? That's cool then.

ahhh.... that means you have a built in amplifier in your stereo system or your speakers. i would think a good EQ would improve your sound more than a separate amplifier unit. you don't normally need to buy an amp for your home stereo unless you're building it yourself one component at a time.