These days the most practical methods for backing up is to another disk drive locally and/or online.

A local backup is useful for being easy to get to for a restore. However if your office or residence suffers a disaster both the computer and the on-site backup would be destroyed.  For this reason it’s important to have an off site backup.  Many people will backup to another external hard driver and then take it to another location such as their office or a trusted friends residence.  This ensures that the data is safe in the event of a disaster.

DVD’s and CD’s have a very small capacity these days, and using them is more of a chore.  If things become a chore to do they will eventually not be done. One of the goals is to make the backup process as easy and painless as possible.  One advantage to DVD’s and CD media is that it can be more reliable.  However if you are going to use this method purchase good quality archival media.