The root account is also called the superuser; it is a login that bypasses all security protection on your system. The root account should be used only to perform system administration and for as short a time as possible.
Any password you create should contain from six to eight characters, and it should contain both uppercase and lowercase characters, as well as punctuation characters. Take extra care when setting your root password, since it is such a powerful account. Avoid dictionary words or use of any personal information that could be guessed.
If anyone ever tells you he needs your root password, be extremely wary. You should normally never give out your root account, unless you are administering a machine with more than one system administrator.