Data, or information stored on your computer, can either be held on fixed disk drives inside the computer or on removable media such as CD's that can be inserted and removed. Removable media can be used to transfer files between computers or to backup the data already existing on fixed disk drives. There are three types of custom metal boxes removable media: Magnetic, Optical and Flash.

 Hard disks, floppy disks and digital audiotape are examples of Magnetic storage. They operate through a read/write head, which creates and reads magnetic impressions on the disk.The downside?The magnetic impression only lasts for around five years

The capacity of most removable magnetic disks is too low for many types of files

Optical storage  Optical Storage holds information in digital form that is written and read by a laser. All CD and DVD devices are examples of this.The upside?Increased capacity: one Optical disc can store the same amount of data as over 500 diskettes

Durability: they last up to seven times as long as Magnetic forms of storageFlash Memory (Solid-State Removable Storage)  Solid-state memory (or Flash memory) is a high-performance plug-and-play storage device that contains no moving parts. It is found in digital cameras, video game consoles and digital audio players. You can use it in the form of USB Flash Drives to transfer or backup data. Flash memory is small, light and fast.

Backup  Backup is the copying of files onto portable media so that if your computer crashes, data won't be lost in oblivion. Backup is usually routine in large businesses but is often neglected by individual users. Some suggest backing up data files and duplicating your hard drive weekly. It takes around 45 minutes to backup a 500-megabyte hard disk.

There are two options - local or Internet backup. The following is a list of Local backup options. Most of these also double as devices used to transfer data between computers.

Internet Backup  Another backup option is sending your files to an Internet site for safekeeping. If your computer crashes you can simply download them from the site. Here are a few examples of such sites: Backup Defender (backupdefender.co.nz) and My Backup (mybackup.co.nz). N.B. The author does not recommend or endorse any of the above service providers.Diskette A Diskette is a 3.5-inch removable magnetic disk. The older version, the floppy disk, is 5.25 inches square and flexible. Copying to a diskette is quick and economical.

Those who use their PC for personal finance - the diskette enables you to retrieve checkbook balances etc.Projects that need to be continuously backed up such as a film script, as it is a cheap alternative.Not so good for?Some newer computer and laptop models that do not have a diskette or floppy drive installed.Large amounts of data as diskettes don't have a great storage capacityZip Drives A Zip drive is a small, square shaped magnetic disk that is ideal for backing up your PC. The 100-megabyte size holds the equivalent of 70 floppy diskettes. 

They seem to be a fleeting technology - most computers do not have a Zip Disc drive installed and opinion varies on how long they will  be around for.  Compact Disks There are different standards of CD's that have different capabilities. Just to confuse us they are recognized by seemingly similar acronyms; CD-R, CD-RW, CD+RW, DDCD and E-CD.

CD-R CD-R (Compact Disc - Recordable) is a CD that can be recorded to only once. It usually holds 74 minutes of audio or 650 MB of data, although newer versions hold up to 80 minutes of audio (700 MB of data). If your PC has CD burning software and a compatible CD-R or CD-RW drive, the CD-R can be used in the same way as a diskette. However unlike a diskette it cannot be deleted or overwritten. Look out for CD-Rs that have an additional protective layer which make them less susceptible to damage caused through scratching.