Glossary
Short definitions for terms that come up across multiple sections but don't warrant their own deep-dive page.
Terms defined once here and linked to from wherever they come up, rather than re-explained on every page that uses them.
Distro (distribution)
A complete, installable operating system built around the Linux kernel - bundling a package manager, init system, default shell, and a curated set of software. See Kernel vs. Distribution.
Daemon
A process that runs in the background, detached from any controlling
terminal, typically started at boot and left running to provide a service
(e.g. sshd, cron). See systemd and Services.
Superuser / root
The account with unrestricted access to the system (UID 0). Most
day-to-day work should happen as a normal user, escalating with sudo
only when needed. See sudo and Privilege.
Shell
The command interpreter that reads what you type (or a script) and runs it. Bash is the default on most distributions. See Bash Basics.
Kernel
The core program that manages hardware, memory, processes, and system calls - the one component every distribution shares. See What Is Linux?.
Mount point
A directory under which a filesystem (a partition, a disk image, a network share) is attached, making its contents appear as part of the main directory tree. See Mounting and fstab.
Environment variable
A named value, inherited by child processes, that configures shell or
program behavior (PATH, HOME, EDITOR). See
Environment Variables.