System Initialization, X Windows, and Localization

Advanced Configuration and Power Interface (ACPI)

A BIOS component that provides hardware and power management event functionality to an operating system.

Unity

A GNOME Shell alternative focused on mobile devices.

daemon

A Linux system process that provides a system service.

target unit

A Systemd term that describes the number and type of daemons running on a Linux system. It is functionally equivalent to the UNIX SysV term runlevel.

target units

A Systemd term that describes the number and type of daemons running on a Linux system. It is functionally equivalent to the UNIX SysV term runlevel.

service unit

A Systemd term that is used to describe a daemon.

service units

A Systemd term that is used to describe a daemon.

secure boot

A UEFI BIOS feature that checks files loaded during the boot process to ensure that they were not modified by malware.

runlevel

A UNIX SysV term that defines a certain type and number of daemons on a Linux system.

UNIX SysV

A UNIX standard that is used to provide the structure of the system initialization process on Linux systems.

GRand Unified Bootloader (GRUB)

A boot loader used to boot a variety of operating systems (including Linux) on a variety of hardware platforms.

UTF-8

A character set that allows programs to represent the characters in the Unicode character set using one to four 8-bit bytes; it is the most common character set used today.

Unicode

A character set that extends ASCII and represents characters used in most languages.

ISO-8859

A character set that extends ASCII to provide additional character mappings for non-English languages.

American Standard Code for Information Interchange (ASCII)

A character set that provides character mappings for English characters.

hwclock command

A command that can be used to view and modify the system clock within the computer BIOS.

X.org

A common implementation of X Windows used in Linux distributions.

XFCE

A common lightweight desktop environment.

kernel panic

A condition in which a system halts immediately after loading the Linux kernel.

multi boot

A configuration in which two or more operating systems exist on the hard disk of a computer; the boot loader allows the user to choose which operating system to load at boot time.

multi booting

A configuration in which two or more operating systems exist on the hard disk of a computer; the boot loader allows the user to choose which operating system to load at boot time.

MATE

A desktop environment based on GNOME and used by Arch Linux.

Cinnamon

A desktop environment based on GNOME and used by Linux Mint.

GTK+ toolkit

A development toolkit for C programming; it is used in the GNOME desktop and the GNU Image Manipulation Program (GIMP).

initramfs

A disk image that contains Linux kernel modules that are needed by the Linux kernel during the boot process.

KDE Display Manager (kdm)

A graphical login screen for users that resembles the KDE desktop.

X Display Manager (xdm)

A graphical login screen.

Universal Access utility

A graphical utility within Fedora Linux used to configure assistive technologies.

Wayland

A new X server designed to replace X.org; it is currently still in development.

LightDM

A program that provides a graphical login screen on Ubuntu systems.

GNOME Display Manager (gdm)

A program that provides a graphical login screen.

upstart

A recent version of the UNIX SysV system initialization process used on modern Linux distributions.

Systemd

A relatively new software framework used on Linux systems that provides a system initialization process and system management functions.

Desktop Bus (D-Bus)

A software component that allows programs running within a desktop environment to easily communicate with one another.

Wayland compositor

A windows manager that is used by the Wayland X server.

Wayland compositors

A windows manager that is used by the Wayland X server.

GRand Unified Bootloader version 2 (GRUB2)

An enhanced version of the original GRUB boot loader. It is the most common boot loader used on modern Linux systems.

Power On Self Test (POST)

An initial series of tests run when a computer is powered on to ensure that hardware components are functional.

locale

Definition: The regional language and character set used on a system.

locale command

Definition: Used to display locale information.

startx command

Definition: Used to manually start X Windows and the default window manager and desktop environment.

runtime configuration (rc) scripts

Scripts that are used during the system initialization process to start daemons and provide system functionality.

initstates

See runlevel.

assistive technologies

Software programs that cater to specific user needs.

window manager

The GUI component that is responsible for determining the appearance of the windows drawn on the screen by X Windows.

Localization

The collection of settings on a system that are region-specific.

X server

The component of X Windows that draws graphics to windows on the terminal screen.

X client

The component of X Windows that requests graphics to be drawn from the X server and displays them on the terminal screen.

X clients

The component of X Windows that requests graphics to be drawn from the X server and displays them on the terminal screen.

mutter window manager

The default window manager for the GNOME 3 desktop environment.

initialize (init) daemon

The first process started by the Linux kernel; it is responsible for starting and stopping other daemons

GNOME Shell

The graphical interface components within the GNOME 3 desktop environment.

GRUB Legacy

The original version of the GRUB boot loader.

GRUB root partition

The partition containing the second stage of the GRUB boot loader and the GRUB configuration file; it is normally a partition that is mounted to /boot.

active partition

The partition that a standard BIOS searches for an operating system on.

Net booting

The process of loading an operating system from across a network; it is often used to load Linux live installation media across a network for installation purposes.

system initialization process

The process that executes the daemons that provide for system services during boot time and bring the system to a useable state.

desktop environment

The software that works with a window manager to provide a standard GUI environment that uses standard programs and development tools.

Qt toolkit

The software toolkit used with the K Desktop Environment.

epoch time

The time format used by the Linux kernel; it is represented by the number of seconds since January 1, 1970.

K Window Manager (kwin)

The window manager that works under the KDE Desktop Environment.

system-config-keyboard command

Used on Fedora Linux systems to configure a keyboard for use by X Windows.

grub2-mkconfig command

Used to build the GRUB2 configuration file from entries within the /etc/default/grub file and /etc/grub.d/ directory.

telinit command

Used to change the operating system from one UNIX SysV runlevel to another.

init command

Used to change the operating system from one runlevel to another.

update-rc.d command

Used to configure UNIX SysV daemon startup by runlevel on Ubuntu Linux systems.

chkconfig command

Used to configure UNIX SysV daemon startup by runlevel.

iconv command

Used to convert data from one character set to another.

runlevel command

Used to display the current and most recent (previous) UNIX SysV runlevel.

dracut command

Used to generate an initramfs.

mkinitrd command

Used to generate an initramfs.

grub-install command

Used to install the GRUB boot loader.

grub2-install command

Used to install the GRUB2 boot loader.

tzselect command

Used to locate the appropriate time zone file for a region.

restart command

Used to manually restart an upstart daemon

start command

Used to manually start an upstart daemon.

service command

Used to manually start, stop, and restart UNIX SysV daemons.

stop command

Used to manually stop an upstart daemon.

reload command

Used to reload the configuration files into memory for an upstart daemon.

systemd-analyze command

Used to view Systemd unit information.

localectl command

Used to view and modify locale information.

timedatectl command

Used to view and set time and time zone information for a system.

status command

Used to view the status of an upstart daemon.

systemctl command

Used to view, start, stop, restart, and reload Systemd daemons, as well as configure Systemd daemon startup during the system initialization process.