B


B-tree

A tree structure for storing database indexes. Each node in the tree contains a sorted list of key values and links that correspond to ranges of key values between the listed values. To find a specific data record given its key value, the program reads the first node, or root, from the disk and compares the desired key with the keys in the node to select a subrange of key values to search. It repeats the process with the node indicated by the corresponding link. At the lowest level, the links indicate the data records. The database system can thus rapidly search through the levels of the tree structure to find the simple index entries that contain the location of the desired records or rows.

backup

A duplicate copy of a program, a disk, or data, made either for archiving purposes or for safeguarding valuable files from loss in case the active copy is damaged or destroyed. Some application programs automatically make backup copies of data files, maintaining both the current version and the preceding version.

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. See also auditing; global group; local group; user rights.

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. See also copy backup; daily backup; differential backup; incremental backup; normal backup.

bad block

A disk sector that can no longer be used for data storage, usually due to media damage or imperfections. Also known as bad sector.

bad sector

A disk sector that can no longer be used for data storage, usually due to media damage or imperfections. Also known as bad block.

Bandwidth

In analog communications, the difference between the highest and lowest frequencies in a spcific 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).

bar code

A machine-readable label that identifies objects, such as physical media.

base file record

The first file record in the master file table (MFT) for a file that has multiple file records. The base file record is the record to which the file s file reference corresponds. See also master file table (MFT).

baseline

A range of measurements derived from performance monitoring that represents acceptable performance under typical operating conditions.

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. See also dynamic disk; extended partition; logical drive; MS-DOS (Microsoft Disk Operating System); primary partition.

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. See also Extensible Firmware Interface (EFI); read-only memory (ROM).

basic volume

A primary partition or logical drive that resides on a basic disk. See also basic disk; logical drive; primary partition.

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. See also American Standard Code for Information Interchange (ASCII); logon script.

bidirectional communication

Communication that occurs in two directions simultaneously. Bidirectional communication is useful in printing where jobs can be sent and printer status can be returned at the same time.

binding

A process by which software components and layers are linked together. When a network component is installed, the binding relationships and dependencies for the components are established. Binding allows components to communicate with each other.

binding order

The sequence in which software components, network protocols, and network adapters are linked together. When a network component is installed, the binding relationships and dependencies for the components are established.

BIOS

See definition for basic input/output system (BIOS).

BIOS parameter block (BPB)

A series of fields containing data on disk size, geometry variables, and the physical parameters of the volume. The BPB is located within the boot sector.

Boot Information Negotiation Layer (BINL) service

A service that runs on the server running Windows 2000 Server that acts on client boot requests.

boot sector

A critical disk structure for starting your computer, located at sector 1 of each volume or floppy disk. It contains executable code and data that is required by the code, including information used by the file system to access the volume. The boot sector is created when you format the volume.

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. See also system volume; volume.

bootable CD

An automated installation method that runs Setup from a CD-ROM. This method is useful for computers at remote sites with slow links and no local IT department. See also automated installation.

bootstrap loader

A program that is run automatically when a computer is turned on, or booted. After first performing a few basic hardware tests, the bootstrap loader loads and passes control to a larger loader program, which typically then loads the operating system. The bootstrap loader typically resides in the computer's read-only memory (ROM). See also read-only memory (ROM).

bottleneck

A condition, usually involving a hardware resource, that causes the entire system to perform poorly.

BounceKeys

A keyboard filter that assists users whose fingers bounce on the keys when pressing or releasing them.

bound trap

In programming, a problem in which a set of conditions exceeds a permitted range of values that causes the microprocessor to stop what it is doing and handle the situation in a separate routine.

Bourne shell

A UNIX command processor developed by Steven Bourne.

browsing

The process of creating and maintaining an up-to-date list of computers and resources on a network or part of a network by one or more designated computers running the Computer Browser service.




Microsoft Windows XP Professional Resource Kit 2003
Microsoft Windows XP Professional Resource Kit 2003
ISBN: N/A
EAN: N/A
Year: 2005
Pages: 338
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