Auxiliary Storage Devices
In addition to your hard drive(s), you will undoubtedly want to install other drives on your homebuilt computer. We're calling these "auxiliary drives" to distinguish them from the hard drive. Auxiliary drives include:
Optical drives include CD-ROM drives, CD-RW drives ("burners"), DVD-ROM drives, DVD+/-RW drives, and Blu-Ray (BD-ROM) drives. They use lasers to read and/or write data. Some optical drives combine various features; for example, there are drives that will read DVD's as well as write CD-R's or CD-RW's.
Unless you are planning on doing a network install, you will need at least one optical drive to install the operating system and other software on your new computer. Most optical drives available nowadays have a SATA interface. If you need an EIDE (PATA) drive, you may have a hard time finding one.
On a personal note, I've found optical drives in general to be the least reliable of all computer hardware. They frequently break down and require replacement, even if they're rarely used. I've also found there to be little difference between optical drives made by different manufacturers. My advice: Choose an OEM drive by a company you've heard of, but don't waste your money on a top-of-the-line drive unless it comes with a super warranty -- and then register the warranty and save the information. Chances are that you're going to need it.
The venerable floppy drive has seen better days. Most new computers don't even come with floppy drives any more. But I still like installing them because they are useful for running bootable diagnostic programs. They're also important in dual boot Windows / Linux machines because sometimes a Windows upgrade will wipe out the Linux bootloader, which can be backed up in advance to a floppy in case that happens.
Finally, I like floppy drives because, like the unappreciated floppy drive, I am getting old...
ZIP drives are high-capacity magnetic drives that can hold 100MB, 250MB, or 750MB of data, depending on the model.
When CD-writers first came out, many predicted the eventual demise of ZIP drives. But the ZIP format has defied the odds and remains a fairly popular removable storage medium. They're somewhat more convenient to use and (in my experience) have a lower failure rate than CDs.
Card readers are not really "drives," per se, but they are treated as such by the operating system. Although commonly called "readers," all card readers can both read and write.
If you do digital photography or have any other reason to move data between your computer and a card storage device, then a built-in card reader / writer will make a very nice addition to your new PC. What I like about them is that I don't have to recharge the camera just to get the pictures on to the computer.
Some card readers also read floppy disks or SIM cards, and some also have USB and/or FireWire ports.
Once the industry mainstay for data backup, tape drives are gradually fading into history as newer, faster, and often less-expensive backup solutions like network backup take their place. Some tape drives can read and write DV tapes from digital camcorders.
I really doubt that too many people reading this page intend to install tape drives. They're expensive, the tapes themselves are expensive, and there simply are better ways to do backup nowadays. But every time I take this section out, I get emails from people asking why. So here it is, you old farts.