Nero is a software program that's very useful for CD and DVD burning, as well as well as video editing and data backups. You don't NEED it, but it's fairly easy to use compared to others and it does quite a bit.
Nero is also a nifty dubstep "group" from the UK that released "Welcome Reality" earlier this year. Good album. Now, that you should hear.
Nero is computer software that is mostly used to burn CDs and DVDs. Some of the other features that are offered by Nero include video editing, video file conversion and back up support. You don't really need it on your computer unless you work with videos a lot.