Account: A user's login and password, plus the files and permissions assigned to each user.
Apache: The most popular Web server in the world, free with Linux.
BSD: Berkeley Software Distribution, a version of Unix which took the first steps from being proprietary to freedom.
Distribution: A collection of Linux programs and utilities along with the operating system. It may include added-value features which the distributor charges for.
GNU: Software and free distribution philosophy of the Free Software Foundation. Explained as "Gnu's Not Unix" - a self-referring acronym which makes it impossible to give the first letter a "real" meaning.
Kernel: The core of the operating system, which calls in other functions as needed. Custom installations allow users to include only what they need in the kernel.
Linux: Strictly, the free operating system, a clone of Unix. Often refers to the OS and a large number of programs included in a "distribution".
Partition: Section of a hard disk prepared for a particular operating system or function.
Root: The top user on a Linux system, also called "superuser". The root account has complete control of the system. Use an ordinary user account for day to day work.
XFree: Free version of the X software which gives Unix systems a graphical interface.