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B
B-channel
A single channel of an ISDN line
that is used to carry either voice or data information. ISDN Basic Rate
Interface (BRI) has 2 B-channels. ISDN Primary Rate Interface (PRI) in
North America has 23 B-channels. ISDN Primary Rate Interface (PRI) in
Europe has 30 B-channels. B-channel is also called bearer
channel.
background
The screen background image used on
a graphical user interface such as Windows. Any pattern or picture that
can be stored as a bitmap (.bmp) file can be set as a screen
background.
background program
A program that runs while the user
is working on another task. The computer's microprocessor assigns fewer
resources to background programs than foreground programs.
backup domain controller
(BDC)
In Windows NT Server 4.0
or earlier, a computer running Windows NT Server that receives a copy
of the domain's directory database (which contains all account and
security policy information for the domain).
The copy is synchronized
periodically and automatically with the master copy on the primary domain
controller (PDC). BDCs also authenticate user logon information and can be
promoted to function as PDCs as needed. Multiple BDCs can exist in a
domain. Windows NT 3.51 and 4.0 BDCs can participate in a
Windows 2000 domain when the domain is configured in mixed
mode.
backup media pool
A logical collection of data-storage
media that has been reserved for use by Microsoft Windows Backup. Backup
uses Removable Storage to control access to specific media within a
library.
backup operator
A type of local or global group that
contains the user rights you need to back up and restore files and
folders. Members of the Backup Operators group can back up and restore
files and folders regardless of ownership, permissions, encryption, or
auditing settings.
backup set
A collection of files, folders, and
other data that has been backed up and stored in a file or on one or more
tapes.
backup set catalog
A summary of the files and folders
that have been saved in a backup set.
backup types
A type that determines which data is
backed up and how it is backed up. There are five backup types: copy,
daily, differential, incremental, and normal.
bandwidth
In analog communications, the
difference between the highest and lowest frequencies in a given range.
For example, an analog telephone line accommodates a bandwidth of 3,000
hertz (Hz), the difference between the lowest (300 Hz) and highest (3,300
Hz) frequencies it can carry. In digital communications, bandwidth is
expressed in bits per second (bps).
Bandwidth Allocation Protocol
(BAP)
A PPP control protocol that is used
on a multiprocessing connection to dynamically add and remove
links.
base priority
A precedence ranking that determines
the order in which the threads of a process are scheduled for the
processor. Use Task Manager to view and change base priorities.
For Message Queuing, a property that
specifies the queue's priority in a public queue. You can set the base
priority from -32,768 to 32,767; the default priority is 0. Private queues
do not support base priority. Message Queuing routes and delivers messages
first by base priority, then by message priority.
basic disk
A physical disk that can be accessed
by MS-DOS and all Windows-based operating systems. Basic disks can contain
up to four primary partitions, or three primary partitions and an extended
partition with multiple logical drives. If you want to create partitions
that span multiple disks, you must first convert the basic disk to a
dynamic disk using Disk Management or the Diskpart.exe command-line
utility.
basic input/output system
(BIOS)
On x86-based computers, the set of
essential software routines that test hardware at startup, start the
operating system, and support the transfer of data among hardware devices.
The BIOS is stored in read-only memory (ROM) so that it can be executed
when you turn on the computer. Although critical to performance, the BIOS
is usually invisible to computer users.
basic storage
A storage method in MS-DOS, Windows,
Windows NT, and Windows 2000 for primary partitions, extended partitions,
and logical drives.
basic volume
A primary partition or logical drive
that resides on a basic disk.
batch program
An ASCII (unformatted text) file
that contains one or more operating system commands. A batch program's
file name has a .cmd or .bat extension. When you type the file name at the
command prompt, or when the batch program is run from another program, its
commands are processed sequentially. Batch programs are also called batch
files.
baud rate
The speed at which a modem
communicates. Baud rate refers to the number of times the condition of the
line changes. This is equal to bits per second only if each signal
corresponds to one bit of transmitted data.
Modems must operate at the same baud
rate in order to communicate with each other. If the baud rate of one
modem is set higher than that of the other, the faster modem usually
alters its baud rate to match that of the slower modem.
Berkeley Internet Name Domain
(BIND)
An implementation of DNS written and
ported to most available versions of the UNIX operating system. The
Internet Software Consortium maintains the BIND software.
binary
A base-2 number system in which
values are expressed as combinations of two digits, 0 and 1.
BIND boot file
Configuration file used by Domain
Name System (DNS) servers running under versions of the Berkeley Internet
Name Domain (BIND) software implementation. The BIND boot file is a text
file, Named.boot, where individual lines in the file list boot directives
used to start a service when the DNS server is started. By default,
Microsoft DNS servers use DNS service parameters stored in the registry,
but they allow the use of a BIND boot file as an alternative for reading
boot configuration settings.
bindery
A database in Novell NetWare
3.x that contains organizational and security information about
users and groups.
bit (binary digit)
The smallest unit of information
handled by a computer. One bit expresses a 1 or a 0 in a binary numeral,
or a true or false logical condition. A group of 8 bits makes up a byte,
which can represent many types of information, such as a letter of the
alphabet, a decimal digit, or other character. Bit is also called binary
digit.
bits per second (bps)
The number of bits transmitted every
second, used as a measure of the speed at which a device, such as a modem,
can transfer data.
boot
The process of starting or resetting
a computer. When first turned on (cold boot) or reset (warm boot), the
computer runs the software that loads and starts the computer's operating
system, which prepares it for use.
boot files
The system files needed to start
Windows. The boot files include Ntldr and Ntdetect.com.
Boot Logging
A process in which a computer that
is starting (booting) creates a log file that records the loading of each
device and service. The log file is called Ntbtlog.txt, and it is saved in
the system root directory.
boot partition
The partition that contains the
Windows operating system and its support files. The boot partition can be,
but does not have to be, the same as the system partition.
boot volume
The volume that contains the Windows
operating system and its support files. The boot volume can be, but does
not have to be, the same as the system volume.
BOOTP extensions
A set of optional information types
defined originally in RFC 1497 for use with BOOTP service and later
supported by DHCP. In DHCP, these extensions form the legacy core set of
client parameters available and supported by most standard DHCP and BOOTP
servers.
bootstrap protocol
(BOOTP)
A protocol used primarily on TCP/IP
networks to configure diskless workstations. RFCs 951 and 1542 define this
protocol. DHCP is a later boot configuration protocol that uses this
protocol. The Microsoft DHCP service provides limited support for BOOTP
service.
broadband
Of or relating to communications
systems in which the medium of transmission (such as a wire or fiber-optic
cable) carries multiple messages at a time, each message modulated on its
own carrier frequency by a modem.
broadband connection
A high-speed connection. Broadband
connections are typically 256 kilobytes per second (KBps) or faster.
Broadband includes DSL and cable modem service.
broadband integrated services
digital network (B-ISDN)
An ITU-T communication standard for
high-speed networking that provides new services, including voice, video,
and data on the same network.
broadcast
An address that is destined for all
hosts on a particular network segment.
browser
Software that interprets the markup
of files in HTML, formats them into Web pages, and displays them to the
end user. Some browsers also permit end users to send and receive e-mail,
read newsgroups, and play sound or video files embedded in Web
documents.
buffer
A region of RAM reserved for use
with data that is temporarily held while waiting to be transferred between
two locations, such as between an application's data area and an
input/output device.
built-in groups
The default security groups
installed with the operating system. Built-in groups have been granted
useful collections of rights and built-in abilities.
In most cases, built-in groups
provide all the capabilities needed by a particular user. For example, if
a domain user account belongs to the built-in Administrators group,
logging on with that account gives a user administrative capabilities over
the domain and the domain servers. To provide a needed set of capabilities
to a user account, assign it to the appropriate built-in group.
bus
A communication line used for data
transfer among the components of a computer system. A bus essentially
allows different parts of the system to share data. For example, a bus
connects the disk-drive controller, memory, and input/output ports to the
microprocessor.
bytes
A unit of data that typically holds
a single character, such as a letter, a digit, or a punctuation mark. Some
single characters can take up more than one byte. |
