HackingTruths Blog

As the previous person answered, it’s common to use
“groups” to give multiple people administrative
permissions. However, in a sense you can also
have multiple “root” accounts.
The point is that “root” is really user ID “0″. The
UID is what matters, not the name. So you can create
another account (with a different name, home directory,
shell, and password), but as long as the UID is 0,
it’s still “root” in the sense that it has complete
administrative permissions.
This “trick” is sometimes done so that the admins at
a site will have a common “root” password for all machines,
but each machine can also have a “local root” so
that the person who sits at that machine can also
administer it (but *only* that machine).
root:x:0:0:root:/root:/bin/bash
lroot:x:0:0:root:/home/localroot:/…
In this example, admins would log in as “root” and
use the home directory “/root” with “bash”. The
owner of the machine could log in as “lroot”, using
a different password, using the “tcsh” shell.
This gives the illusion of multiple accounts, but since
they have the same UID, they’re really the same user.