What's a Repeater Input?

I was reading something about bootleggers on GMRS and the term came up.It’s pretty much self explanatory of what it is,but how does it work,will it give you a GPS location.

Repeaters work using two frequencies.
One is the input, the other is the…output.
A radio you use must be capable of repeater use by transmitting on one frequency and receiving on another.

For instance the input for GMRS frequency 462.6000 is 467.6000. So when you key up the radio goes into transmit (TX) mode on 467.6000. As soon as you unkey it goes into receive (RX) mode on 462.6000.
This allows you to talk TX and at the same time the other people can RX in real time since the repeater is RXing and TXing at the same time. This would not be possible if only one frequency was used.

Get it?

Here: http://www.hamuniverse.com/repeater.html

I actually got it from this phrase and thought it was a thing that could locate the radio,as it was talking about boot leggers.So maybe I didn’t know what it was.

‘‘Listen on the repeater input to see if you hear his input signal. If you develop information on the identify of a bootlegger inform the local FCC field office. The Personal Radio Association has active enforcement program and can help you learn to identify persistent bootleggers.’’

Here’s what I think this means. I’m not an expert in any way however.
-I believe that you can use triangulation to determine the location of a radio transmitter.
-if you want to finder the bootlegger, you need to triangulate on the signal that he is transmitting (the repeater input frequency)
-if you triangulate on the repeater output frequency, you will be locating the repeater, not the bootlegger.