Glossary 163CD-RW/DVD drive — A drive, sometimes referred to as a combo drive, that can readCDs and DVDs and write to CD-RW (rewritable CDs) and CD-R (recordable CDs)discs. You can write to CD-RW discs multiple times, but you can write to CD-R discsonly once.clock speed — The speed, given in MHz, that indicates how fast computercomponents that are connected to the system bus operate.CMOS — A type of electronic circuit. Computers use a small amount of battery-powered CMOS memory to hold date, time, and system setup options.COA — Certificate of Authenticity — The Windows alpha-numeric code located on asticker on your computer. Also referred to as the Product Key orProduct ID.Control Panel — A Windows utility that allows you to modify operating system andhardware settings, such as display settings.controller — A chip that controls the transfer of data between the processor andmemory or between the processor and devices.CRIMM — continuity rambus in-line memory module — A special module that hasno memory chips and is used to fill unused RIMM slots.cursor — The marker on a display or screen that shows where the next keyboard, touchpad, or mouse action will occur. It often is a blinking solid line, an underline character,or a small arrow.DDDR SDRAM — double-data-rate SDRAM — A type of SDRAM that doubles thedata burst cycle, improving system performance.DDR2 SDRAM — double-data-rate 2 SDRAM — A type of DDR SDRAM that uses a4-bit prefetch and other architectural changes to boost memory speed to over 400MHz.device — Hardware such as a disk drive, printer, or keyboard that is installed in orconnected to your computer.device driver — See driver.DIMM — dual in-line memory module — A circuit board with memory chips thatconnects to a memory module on the system board.DIN connector — A round, six-pin connector that conforms to DIN (DeutscheIndustrie-Norm) standards; it is typically used to connect PS/2 keyboard or mousecable connectors.disk striping — A technique for spreading data over multiple disk drives. Disk striping
