Sorting through the Different Types of Disk Drives

[Lyte]

Sorting through the Different Types of Disk Drives
Adapted From: Buying a Computer for Dummies: 2006

When you're done working, you need a permanent place to store your stuff in the computer. The hardware to meet that requirement is the disk drive - specifically, the computer's hard drive. You direct the software that you're using to "save" your stuff on the hard drive, by making a permanent copy that you can use later.

• The most popular, inexpensive, and reliable form of permanent storage is the hard drive.
• Some computers even have several forms of disk storage: a hard drive, CD-ROM drive or DVD drive (or both), and maybe a floppy drive. Each of these has specific uses.
• Some handheld computers don't have physical disk drives. Instead, they contain special memory that isn't erased when the power is turned off.
• Some advertisements refer to permanent storage as "disk memory." Although that term is technically correct, the term is confusing. Don't mistake disk memory for the memory inside your computer. Disk storage and RAM are two different places in a computer.

What is a disk, and what is a drive?

Simply put, the drive is the thing that contains or eats the disk. So, although your computer has a hard disk, it's more proper to say "hard drive." Similarly, you may have a CD-ROM drive, floppy drive, DVD drive, and even a digital media drive.

The disk is literally a disk. The computer writes information to the disk, where it's stored exactly like information is recorded on a cassette tape, only the disk media is flat and round - like a pancake. The drive is the device that spins the disk, reading and writing information. Sometimes, hard drives are referred to as fixed disks. This means that the disk is "fixed," as in nonmovable.

With some drives, the disk can be removed. This is true for CD-ROM, DVD, floppy, and other removable disks. With the hard drive, however, the disk cannot be removed. That's because the disk (or disks) inside the drive needs to be hermetically sealed to avoid contamination by rogue particles in the air.

Below is a cross section of a typical hard drive. The entire unit is the hard drive. Inside the unit are the hard disks.


Disk and Disk drive