Glossary of common terms

Introduction

Linux terms can be confusing and offputting at first, so this Glossary provides a list of the ones used in this Manual to get you started. For more help on the terms used in the Linux computer world, see Links and Guides.

If you reached this page by clicking on a green glossary link, use your browser's [<—]   back button to return you to your previous page.


Terms

backend:   Also back-end. The backend includes the various components of a program that process the user input entered through the frontend. See also frontend.

backport:   Backports are new packages that have been recompiled to run on a released distribution in order to keep it up-to-date.

BASH: The default shell on most Linux systems as well as on Mac OS X, BASH is an acronym for Bourne-again shell. For more information, see Links and Guides at the bottom of the page.

BitTorrent:   Also bit torrent or torrent. A method invented by Bram Cohen to distribute large files without the need for a single individual to provide the hardware, hosting and bandwidth resources required.

Boot options:   Also cheat codes. Additional boot and kernel commands available to modify the boot and installation procedures. An example is “vga=normal” which tells the system to disable the default resolution, often used for older monitors.

chainloading:   Also chain loading. Instead of directly loading an operating system, a boot manager like GRUB can use chain loading to pass control from itself to a boot sector on a hard disk partition. The target boot sector is loaded in from disk (replacing the boot sector from which the boot manager itself was loaded) and the new boot program is executed. In addition to when it is necessary, as in booting Windows from GRUB, the advantage to chainloading is that each operating system on the hard disk drive —and there could be dozens— can be responsible for having the correct data in it's own boot sector. So GRUB residing in the MBR need not be rewritten every time there are any changes. GRUB can simply chainload the relevant information from the boot sector of a given partition whether it has changed or remained the same since the last boot time.

cloop error:   A failure to read a block of compressed data. CLOOP is shorthand for compressed loopback device, a linux kernel module that allows a compressed filesystem to be read, such as is used on a MEPIS LiveCD.

command line interface (CLI):   Also known as console, Konsole, terminal, command prompt, shell, or bash. This is a UNIX-style text interface, which MS-DOS was also designed to resemble. A root console is one where administrative privileges have been acquired after entering the root password.

desktop environment:    The software which provides a graphical desktop (windows, icons, desktop, task bar, etc) for an operating system user. MEPIS integrates the KDE desktop and configures it to feel familiar to both Windows® and Mac OS X® users.

disk image:    A file containing the complete contents and structure of a data storage medium or device such as a hard drive or DVD. See also ISO.

file system:    Also filesystem. This refers to the way that files and folders are logically arranged on a computer's storage devices and it can also refer to the type of formatting on a storage device, such as the common Windows formats NTFS and FAT32, or the Linux formats EXT3 or ReiserFS.

free-as-in-speech:   The English word “free” has two possible meanings: 1) without cost, and 2) without restrictions. In part of the open-source software community, an analogy used to explain the difference is 1) “free” as in beer vs. 2) “free” as in speech. The word freeware is used universally to refer to software that is simply without cost, whereas the phrase free software loosely refers to software that is more properly called open-source software, licensed under some type of open source license such as the GPL.

frontend:    Also front-end. The front-end is the part of a software system that interacts directly with the user. See also backend.

GPL:   The GNU General Public License. This is a license under which many open-source applications are released. It specifies that you may view, modify, and redistribute the source code of applications released under it, within certain limits; but that you may not distribute the executable code unless you also distribute the source code to anyone who asks for it.

Graphical User Interface (GUI):   This refers to a program or operating system interface that uses pictures (icons, windows, etc), as opposed to text (command-line) interfaces.

home directory:   One of the 17 top-level directories branching from the root directory in MEPIS Linux, /home contains a subdirectory for every registered user of the system. Within each user's home directory s/he has full read-write privileges. Further, most of the user-specific configuration files for various installed programs are stored in hidden subdirectories within the /home/username directory —as is downloaded email. Other downloaded files usually go by default into the home/username/Documents or /home/username/Desktop subdirectories.

ISO:   A disc image following an international standard that contains data files and filesystem metadata, including boot code, structures, and attributes. This is the normal method for delivering Linux versions such as MEPIS over the Internet. See also disk image.

kernel:   The layer of software in an operating system that interacts directly with the hardware.

Kicker:   The panel in KDE that appears by default at the bottom of the screen and contains navigation icons, open (minimized) programs and system notifications. It is highly configurable, and can include a utility to switch between any of several desktops you can run simultaneously, if your primary desktop surface tends to get cluttered with open programs. For a graphic and a short explanation of its default appearance, see Section 3.4.

LiveCD:   A bootable compact disc from which one can run an operating system, usually with a complete desktop environment, applications, and essential hardware functionality. In 2003, MEPIS was the first distribution of Linux to include a GUI-based Installer application on the desktop of a fully functional LiveCD, so a separate Installation CD was no longer needed. Simultaneously, MEPIS was also the first Linux to include GUI-based tools, now called Assistants, on the LiveCD to help a user repair a broken system.

MBR:   Master Boot Record: the first 512-byte sector of a bootable hard disk drive. Special data written to the MBR enables the computer's BIOS to pass the boot process off to a partition with an installed operating system.

md5sum:   A program that calculates and verifies a file's integrity. The MD5 hash (or checksum) functions as a compact digital fingerprint of a file. It is extremely unlikely that any two non-identical files will have the same MD5 hash. Because almost any change to a file will cause its MD5 hash to also change, the MD5 hash is commonly used to verify the integrity of files.

mirror:   Also mirror site. An exact copy of another Internet site, commonly used to provide multiple sources of the same information to supply reliable access to large downloads.

module:   Modules are pieces of code that can be loaded and unloaded into the kernel upon demand. They extend the functionality of the kernel without the need to reboot the system.

mountpoint:   The place on the root filesystem where a fixed or removable device is attached (mounted) and accessible as a subdirectory. All computer hardware needs to have a mountpoint in the filesystem to be usable. Most standard devices such as keyboard, monitor and your primary hard disk drive are mounted automatically at boot.

NTFS®:   Microsoft's New Technology File System debuted in 1993 on the Windows NT Operating System, geared to business networks, and with revisions entered the mainstream Windows users' desktop computers in later versions of Windows 2000. It has been the standard file system since Windows XP was introduced in late 2001. Windows gurus dubbed it Not That FAT System, referring to its many advantages in security and disk maintenance over the File Allocation Table filesystem Microsoft had previously used. Many Unix/Linux gurus were not so impressed with Microsoft's efforts at reinventing a Unix-style filesystem, and “backronymed” it as the “ Nice Try File System.”. In all honesty, it was a much-needed and successful advance over the FAT, but until 2006 posed a problem for Linux users, since it's proprietary code base made it a challenge to successfully write to from within Linux. Open-source programmers have since overcome that challenge, and it is no longer necessary to create partitions using the antiquated FAT filesystem in order to share data from Windows.

open-source:   Software whose source code has been made available to the public under a license that allows individuals to modify and redistribute the source code. In some cases, open-source licenses restrict the distribution of binary executable code. For more information visit the Open Software Initiative (link below).

package:   A package is a discrete, non-executable bundle of data that includes instructions for your package manager about installation. A package doesn't always contain a single application; it might contain only part of a large application, several small utilities, font data, graphics, or help files.

package manager:   A package manager such as (Synaptic or KPackage) is a collection of tools to automate the process of installing, upgrading, configuring, and removing software packages.

port:   A virtual data connection that can be used by programs to exchange data directly, instead of going through a file or other temporary storage location. Ports have numbers assigned for specific protocols and applications, such as 80 for HTTP, 5190 for AIM, etc.

repo:   See repository.

repository:   A software repository is an internet storage location from which software packages may be retrieved and installed via a package manager. In MEPIS Linux, the repository list file (/etc/apt.sources.list) is typically modified through the default package manager Synaptic.

script:  An executable text file, containing commands in an interpreted language. Usually refers to BASH scripts which are used extensively "under the hood" of the Linux operating system, but other languages may be used as well.

source code:   The human-readable code in which software is written prior to being assembled or compiled into machine-language code.

switch:   A switch (also flag, option or parameter) is a modifier appended to a command to change its behavior. A common example is -R (recursive), which tells the computer to carry out the command through all subdirectories.

tarball:   An archiving format, like zip, popular on the Linux platform. Unlike zip files, though, tarballs may use one of a number of different compression formats, such as gzip or bzip2. They usually end in file extensions like .tgz, .tar.gz, or .tar.bz2. Many archive formats are supported in MEPIS with a graphical application called Ark. Usually an archive can be extracted simply by right-clicking on it in KDE.

window manager:   A component of a desktop environment that provides the basic maximize/minimize/close/move functions for windows in the GUI environment. Sometimes it can be used as an alternative to a full desktop environment. In MEPIS, the default window manager is called KWin, and is an integral part of the K Desktop Environment (KDE). In antiX, the default is Fluxbox, a very light windows manager that requires very little graphics and system RAM.

Unix:   Also UNIX. The operating system which Linux is modeled after, developed in the late 1960's at Bell Labs and used primarily for servers and mainframes. Like Linux, Unix has many variations.

X:   Also X11, xorg. The X Window System is a networking and display protocol which provides windowing on bitmap displays. It provides the standard toolkit and protocol to build graphical user interfaces (GUIs) on Unix-like operating systems and OpenVMS, and is supported by almost all other modern operating systems.