Access Server

I’m looking into speeding up our dial-in users.

Looking at a access server that connects to a T1 one line. It comes with modems. What are the modems for? If the user dials up and connects to the server through the T1 line, what do the modems do?

Does the T1 actually go to the modems first, then to the access server for connection to our LAN.

I know modems convert the analog to digital signal and back again. I just don’t understand where the modems come into play in this setup.
TM