Time Machine has lots of great features. It is automatic, backing up every hour without any user intervention. By default, it will copy everything on your Mac including system files, applications, accounts, preferences, email messages, music, photos, movies, documents, and more.

The best part of Time Machine is its ability to keep multiple copies of files. Any time a file is changed, Time Machine backs it up, making recovery of a specific version of a file fast and simple.

Since Time Machine will do this until the hard drive becomes full, I suggest dedicating an entire hard drive to it, and one that is at least twice the size of your internal disk. The bigger the drive, the more Time Machine's archives can hold.

To set up Time Machine, plug in your secondary hard drive. When your Mac asks whether you want to use it for a Time Machine backup, click the "Use as Backup Disk" button. This step is really all you need to do, unless you want to customise which files are backed up.

You can also backup multiple Macs at the same time by using Apple's Time Capsule, which is a wireless hard drive and access point dedicated to be used with Time Machine. This can be configured on all of your Macs at home - so be sure to get a Time Capsule big enough to back up all of them. They come with a 2TB or 3TB hard drive built in.

Robert Morgan is the managing director at PIT Group.