Optical drives, which write to recordable CDs or DVDs, are quickly becoming standard equipment on new PCs. CD-Rs and CD-RWs (on which data can be rewritten) are inexpensive and have a capacity of at least 650 MB. DVDs can hold up to 4.7GB, and up to 9.4GB in the case of double-sided DVDs. The convenience, compatibility and relatively low cost make optical drives a good choice for making backups, particularly for home users.
Tape Drives
The longtime popularity of tape drives as a backup solution is largely due to their inexpensiveness and high data capacity (which can be as much as 50 GB). On the other hand, it takes a long time to find certain files on a tape, or to restore an entire tape. Tapes are generally best suited to small businesses and those who need to back up very large amounts of data.
External Hard Drives
External hard drives can be a great backup solution, not only because of their very large capacity, but also because of their speed and ability to run other programs and store files that may no longer fit on your primary hard drive. These drives are fairly expensive (ranging from $100 to $400 for a high-capacity, ultra-portable model), but there is no need to spend more on removable discs. Be sure to choose a model that is compatible with your computer; many require nothing more than a USB or FireWire connection.
Removable Hard Drives
Removable hard drives have one main advantage: they can store large volumes of data, which can be given to someone else. Removable drives have two significant downsides, however: they are expensive, and removable disks are often incompatible with drives of other manufacturers.
Floppy Disks
For people who use their computers as little more than a glorified typewriter, making backups using floppy disks may be sufficient. For most users, however, floppy disks' extremely low capacity (just 1.44 MB) is inadequate to make them a practical choice for anything but transferring a file from one computer to another. But even for that purpose, the floppy disk remains less reliable than alternatives such as flash drives or recordable CDs.
