Glossary

The access permissions define which user group a new user is assigned to and the resulting permissions. The access permissions are generally set by the system administrator.

Access Control List. A set of data that informs a computer's operating system which permissions, or access rights, that each user or group has to a specific system object, such as a directory or file. Each object has a unique security attribute that identifies which users have access to it, and the ACL is a list of each object and user access privileges such as read, write, or execute.

Asymmetric Digital Subscriber Line. Transmission procedure that transmits data about 100 times faster than ISDN in the telephone network.

Accelerated Graphics Port. High-speed slot for graphics cards based on PCI but offering a larger bandwidth. In Contrast, AGP graphics cards can revert directly (without routing around the processor) to the random access memory and main memory, to swap graphics data there.

Advanced Technology Attachment Packet Interface. Type of CD-ROM drive that is connected to an (E)IDE controller. Apart from ATAPI drives, there are SCSI CD-ROM drives, handled by a SCSI controller, and proprietary CD-ROM drives that use their own controller or are connected to a sound card.

Maximum load capacity of a data channel.

Basic Input/Output System. Small component responsible for the initialization of important hardware processes. This essential procedure is complete when the boot menu appears on the screen.

Personal collection of interesting Web page or file references directly accessible in the browser.

Program that searches and displays contents. Today it is mostly used for programs that graphically display contents of World Wide Web pages.

Workstation in a computer network using the services of a server.

Compressor/Decompressor. A codec is any technology for compressing and decompressing data. Codecs can be implemented in software, hardware, or a combination of both. Some popular codecs for computer video include MPEG, Indeo, and Cinepak.

Text-based mode of operating in which commands are entered at a prompt. A command line can be accessed from within a graphical environment as well as from virtual consoles.

Formerly synonymous with terminal. In Linux, there are several virtual consoles that allow the screen to be used for several independent, parallel work sessions.

Disk and Execution Monitor. Program that monitors in the background and comes into action when required. Daemons answer FTP or HTTP requests, for example, or control activity in the PCMCIA slots.

Direct Display Channel. Communication standard between the monitor and the graphics card which transmits various parameters, such as monitor name or resolution, to the graphics card.

Domain Name System. System that converts name-based addresses to TCP/IP addresses and vice versa.

Enhanced Integrated Drive Electronics. Improved IDE standard that allows hard disks with a size greater than 512 MB. See also IDE.

A shell usually provides an environment in which the user can perform temporary settings. These settings include path specifications for programs, the username, the current path, and the appearance of prompts. The data is saved in an environment variable. The assignment of the environment variables is possible, for example, by means of the configuration files of the shell.

Position in the environment of the shell. Every environment variable has a name that is usually capitalized. The variables are assigned values, such as pathnames.

Second Extended File System. Default file system used by Linux.

Protects a local network or host from unauthorized access from the Internet using various security measures.

See GNU.

File Transfer Protocol. Protocol based on TCP/IP for transferring files.

GNU Network Object Model Environment. User-friendly graphical desktop environment for Linux.

Project of the Free Software Foundation (FSF).The aim of the GNU Project is to create a free UNIX-compatible operating system—free not so much in the sense of free of cost, but in the sense of freedom: having the right to obtain, modify, and change the software. To guarantee the freedom of the source code (the actual program code), every change of the original code must be free as well, so modifications of or additions to the original software cannot compromise this freedom in any way. The now classic GNU Manifesto (http.//www.gnu.org/gnu/manifesto.html) explains many aspects of this thinking. In legal terms, GNU software is protected by the GNU General Public License or GPL (http.//www.gnu.org/copyleft/gpl.html) and by the GNU Lesser General Public License or LGPL (http.//www.gnu.org/copyleft/lgpl.html).

In connection with the GNU Project, all UNIX tools and utilities are being redeveloped and, in part, provided with more or enhanced functionalities. Even complex software systems, such as Emacs or glibc, are integral components of the project.

The Linux kernel, subject to the GPL, profits from this project (especially from the tools), but should not be seen as the same thing.

GNU General Public License. See GNU.

Private directory in the Linux system that belongs to a specific user (usually in /home/username). Except for the superuser root, only the home directory owner has full access rights to his home directory.

Name of a machine in Linux, usually the name by which it can be reached on the network.

Hyper Text Markup Language. Most important language used in the World Wide Web for designing the contents. The layout commands made available by HTML define how a document looks and how it is displayed in a browser.

Hyper Text Transfer Protocol. Protocol used between the browsers and Internet servers to transmit HTML pages over the World Wide Web.

Integrated Drive Electronics. Widely used hard disk standard in low-grade and middle-grade PCs.

Numerical 32-bit Internet address, appearing in four decimal series separated by periods (for example, 192.168.10.1), which is uniquely assigned to a machine connected to TCP/IP networks.

Interrupt Request. Request to the operating system carried out by a hardware component or a program to assign it processor capacity.

Integrated Services Digital Network. Popular digital standard for high-speed data transfer over the telephone network.

K Desktop Environment. User-friendly graphical desktop environment for Linux.

The central core of any operating system. It manages memory, contains the drivers that enable communication with the hardware, and handles processes and tasks. Applications run on top of the kernel.

Linux Loader. Small program installed in the boot sector of the hard disk that can start not only Linux but other operating systems as well.

Pointer to a file, widely used in the Internet as well as in the Linux file system. In Linux, there is a distinction made between hard and symbolic links. Although hard links refer to the exact position in the file system, the symbolic link only points to the respective name.

High performance UNIX-like operating system core distributed freely under the GPL (GNU). The name is an acronym (LINUS’ uniX) and refers to its creator, Linus Torvalds. Although the name, in a strict sense, refers only to the kernel itself, the popular understanding of the term usually includes the entire system.

Manual Pages. Traditional documentation for UNIX systems, which can be read using the man command.

Master Boot Record. First physical sector of the hard disk from which the content is loaded to the main memory and executed by the BIOS. This code then loads either the operating system from a hard disk partition or a more sophisticated boot loader, such as LILO.

Algorithm for generating check sums.

Insertion of file systems into the directory tree of the system.

Very efficient compression procedure for audio files that reduces the size by a factor of ten, in contrast to an uncompressed audio file.

Network File System. Protocol for accessing a file system shared over a network.

Network Information Service. Centralized data administration system in networks. Usernames and passwords can be simultaneously managed network-wide by NIS.

Logical, independent section of a hard disk. Each partition can contain different file systems. In Windows, also known as drives.

Unique description of a file’s position in a file system.

Personal Computer Memory Card International Association. An organization consisting of companies that have developed a standard for small, credit card-sized devices, called PC Cards. Originally designed for adding memory to portable computers, the PCMCIA standard has been expanded several times and is now suitable for many types of devices. In general, you can exchange PC Cards on the fly, without rebooting your computer. For example, you can slip in a fax modem card when you want to send a fax and then, when you're done, you can replace the fax modem card with a memory card.

Automatic hardware component configuration technology. Resources, such as IRQ and DMA, are configured and managed separately from the system.

Execution of a program by the processor. In Linux, started programs or executable files run as processes, often referred to as tasks. Processes can be controlled by commands entered in the shell.

Brain of every computer, working through and performing commands given by a user or a program in machine language. The processor has control over the entire system and is responsible for the actual performance of the computer.

See command line.

Standard specifically defined for regulating communication for hardware, software, or networks. There is a multitude of these standards. The most common examples are HTTP and FTP.

Most commonly used cache implemented by Internet providers that stores frequently requested contents in a database to allow other machines requesting those pages to load them directly from it. This process not only reduces the time it takes to download this information, but also conserves the available bandwidth.

File system that logs its changes to a journal. Compared to Ext2, this features allows a file system to be restored very speedily. ReiserFS is optimized for small files.

User undertaking the configuration and maintenance of a complex computer system, such as a network. This system administrator is usually the only person who has access to all parts of the system (root permissions).

The base directory of the file system that does not have any parent directory (all other directories have a parent directory). In UNIX, the root directory is represented as a slash (/).

Small Computer Systems Interface. Hard disk standard implemented in servers and other high-level machines because of its high-speed performance.

Especially flexible command line often equipped with its own specific programming language. Examples are BASH, sh, and tcsh.

Simple Mail Transfer Protocol. Protocol for transferring e-mails.

Secure Socket Layer. Encryption procedure for transferring HTTP data.

See root.

See root.

See process.

Internet communication protocol finding increased use in local networks, known as intranets.

Protocol and command for communicating with other hosts. Normally, the user sees Telnet only as a means for logging in to a remote system.

Designation of a keyboard and monitor combination connected to a central computer. On workstations, this term is also used for programs that emulate a real terminal.

Operating system that is widely distributed, mostly on workstations in networks. Since the beginning of the 1990s, there has been a freely available version for PCs: Linux.

Uniform Resource Locator. Unique Internet address that contains the type (for example, http://) and the name of the host (for example, www.suse.de).

See home directory.

Video Electronics Standard Association. Industrial consortium that defines, among other things, important video standards.

Layer that interacts between the X Window System and the user. It is responsible for, among other things, the desktop display. There is a wide variety of window managers available, one of the more popular ones being kwm for KDE.

World Wide Web. Based on the HTTP protocol, this is a hyperlinked collection of documents, files, and images that can be viewed with a Web browser.

Standard for graphical interfaces in Linux. It is the middle layer between the hardware and the window manager, such as KDE or GNOME.

See X Window System.

Yet another Setup Tool. The SUSE LINUX system assistant.