Quantum DLT 2000 Handbook page 191

Backup. A copy of a file, directory, or volume on a separate
storage device from the original, for the purpose of retrieval in
case the original is accidentally erased, damaged, or destroyed.
Backup Window. The period of time used to back up critical
databases and other information. With an increasing number of
companies running 7x24 applications, the backup window in
many cases is either shrinking or closed.
Backward Compatibility. The capability of all DLTtape drives to
read tapes written on previous generations of DLTtape drives.
Preserves the end users' investment in DLTtape media and drives.
Bad Data Block. A block that cannot reliably hold data because of
a media flaw or damaged format markings.
Bar Code Reader. A scanning system used in many large tape
libraries to inventory tape cartridges and identify cartridge content
by recognizing assigned codes.
Bezel. (Also known as the faceplate.) A plastic panel that extends
the face of a drive so that it covers a computer's drive bay opening.
The bezel usually contains a drive-activity LED.
Bit. Abbreviation for binary digit. A binary digit may have one of
two values: 1 or 0. This contrasts with a decimal digit, which may
have a value from 0 to 9. A bit is one of the logic 1 or logic 0
binary settings that make up a byte of data. See also byte.
Block. A sector or group of sectors. By default, a sector of data
consists of 512 bytes.
Buffer. An area of RAM reserved for temporary storage of data
that is waiting to be sent to a device. The data is usually on its way
to or from the hard disk drive or some other peripheral device.
Bus. The part of a chip, circuit board, or interface designed to
send and receive data.
QUANTUM DLTtape HANDBOOK G.3