In Mac OS X, the root account is disabled by default. The first user account created is added to the admin group and that user can use the sudo command to execute other commands as root. The conventional wisdom is that sudo is the most secure way to run root commands, but a closer look reveals a picture that is not so clear.
This article will only interest Linuxheads, but it’s a great read. It mentions Mac OS, but a few linux distros such as Ubuntu only allow Sudo as well. You can check out the full read at Linuxbox Admin.