Disk - The device used by the computer to store and retrieve information. Disk can refer to a diskette or a hard disk.

Diskette - A removable disk, also called a floppy.

Hard drive - The drive installed inside your computer that stores all your system and data files. Depending on its configuration, the computer may have more than one hard drive. Each drive is assigned its own drive letter. If you have only one drive, its drive letter is C, and it is often called “the C drive.”

I/O - Input/output. Refers to devices, such as printers, whose purpose is to enter data into a computer or extract data from a computer. An I/O device is accessed through an I/O address: a location in memory reserved for the device to exchange information between itself and the rest of the computer.

IRQ - Interrupt request line. The IRQ is a hardware line that a device uses to signal the processor when the device needs the processor’s services. The number of IRQs is limited by industry standards.

Operating system - A program that supervises the computer’s operation, including handling I/O, networking and connectivity, and device drivers.

Path - A sequence of information that directs the system to the file it needs. For example, c:\windows\bubbles.bmp is the path to a graphics file on your system. The c: tells the system it is on the C hard drive, the \windows tells the system it is in the windows folder, and bubbles.bmp is the file.

Pixel - A pixel is an individual dot in a graphic displayed on your computer. Pixels are so close together that they look as though they are connected.

POST - Power-on self-test. POST tests your computer’s components whenever you turn on the computer.

Programs - Software installed on your system. Programs are sometimes called applications.

RAM - Random access memory. RAM is the computer’s system memory. You can write to and read from RAM. Information stored in RAM is temporary and is erased when the computer is turned off.

Appendix 31