Read

To copy data from one area to another. For example, when you open a text file stored on disk, the computer reads the data from the disk and displays it on the screen.

Read/write head

The physical device inside a disk drive that reads and records data on the magnetic surface of a disk.

Real-time clock

A battery-powered clock in the computer that keeps track of the current time and date even when the computer’s power is turned off.

Reset

To reload a computer’s operating system so you can retry a task or begin using a different operating system. Resetting erases the computer’s RAM.

R G B

Red-Green-Blue. A type of color monitor.

R O M

Read Only Memory. The portion of the computer’s memory that contains permanent instructions and cannot be modified. The power-on diagnostic programs, for example, are stored in ROM. Unlike RAM, ROM retains its contents even after you turn off the computer.

Root directory

The top-level directory on a diskette or hard disk. The root directory is designated by a backslash (\ ). All other directories are subdirectories of the root directory or of other subdirectories.

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