I see this often but can't seem to find any info on this, so figured it was time to ask. What does chrooted mean?

When I typed man chroot in my terminal, I got this:

NAME
chroot - run command or interactive shell with special root directory

SYNOPSIS
chroot NEWROOT [COMMAND...]
chroot OPTION

DESCRIPTION
Run COMMAND with root directory set to NEWROOT.

--help display this help and exit

--version
output version information and exit

If no command is given, run ‘‘${SHELL} -i’’ (default: /bin/sh).

chroot "Change Root" is a program which, for a certain localised scope, changes what the user or system sees as it's root direcotry, /. this is often used to create a "Chroot Jail" which is a small pseudo file system from which the user can not escape, as when they might actually really be in /home/jail/usr/share or something, they will actually be seeing it as just /usr/share. consequently it is impossible to get up to the real root, as you can't get out of /home/jail/ as that login thinks that that IS the root.

Chroot can also be used for things like moving live operating systems between disks, such as during an installation of Gentoo.

Oh so if a ftp user is chrooted it means their root directory will be / ?

no, it means that their root directory will be whatever you've set it to be, whatever the ftp server admin wants it to be.

Let's say that I have built a new Linux system in a directory called /usr/pub/newlinux and now I wish to test it... all except its kernel anyway... to see if I've omitted something.

I can use the chroot (change root .. not an elegant cigarette-holder) command to enter an environment under which /usr/pub/newlinux is my "root directory." With few exceptions, no other files outside of that directory and its descendents appear to exist. I can now test my new build in a pretty-good simulation of how things will be when I install and boot that system.

chroot is also used to build so-called "chroot jails" around services, particularly those used by Internet visitors. It is used as a way to make it impossible for rogues who may wish to take-over those services either to see or to reach "the rest" of a system. They are "in jail" and can't get out.

Oh ok I see, so you turn /some/path into / virtually.