I have a few questions. What is an aerator in relation to plumbing and what does it look like and where is it located?

An aerator is a screen fitting on the end of a spigot usually in the bathroom or kitchen sink. It breaks up the water stream and causes bubbles to form so you don't splash your hands of dishes. They always can be un screwed from the spigot since cleaning and replacement is inevitable.

I have a few questions. What is an aerator in relation to plumbing and what does it look like and where is it located?

A aerator'(see image) s a device that installs on a faucet spout and interjects air into the stream so it doesn't splash.
To find one look on the end of your kitchen faucet. :D Cheers, Tom

An aerator is a screen device located at the outlet of spout on bathroom sink and kitchen sink fuacets, and on some jacuzzi spouts..

Wow guys, you beat me to it.

I type way faster than you two guys but lack those pretty pics.

Aerator is... hmmmm... look above for definition:D