Hard Disc Backup

A backup can be just a copy of all the files you've created (you could do this from time to time onto CDs) or it can include all the files on your hard disc. This is known as a clone. The advantage of making a clone on an external drive is that if your normal hard drive fails, you can start your Mac from the external clone.

Note that you cannot make a clone just by dragging all the files across from your hard disc to the external disc. You need software to do this for you.

Alternative procedures

• You can clone your hard drive every time, allowing the new clone to overwrite the old one.
• You can make an 'incremental' clone - i.e. the software will only copy the files which have changed since the last backup. Saves a lot of time.

Partitions

Your external drive can be split into partitions which act as if they were separate drives

• You can have one partition and overwrite it with each successive backup.
• You could have two or more partitions (if the drive is large enough) and alternate them so that you have a recent and an older version of your files available.