connectivity, printing, or e-mail.

Now press u and give top your username when it asks. The u command asks to
see only those processes belonging to you; it allows you to ignore all the
daemons and whatever other people are doing. You might notice bash, the
name of your shell. You'll pretty much always be running bash.

Note that column two of the top display shows you the PID, or Process
IDentification number. Each process is assigned a unique PID. You can use
the PID to control individual processes (more on that later). Another
useful trick is to press ? to get a list of top commands.

You may wonder about the difference between a ``process'' and a
``program.'' In practice, people use the terms interchangeably.
Technically, the program is the set of instructions written by a
programmer and kept on disk. The process is the working instantiation of
the program kept in memory by Linux. But it's not that important to keep
the terms straight.

Much of your interaction with a computer involves controlling processes.
You'll want to start them, stop them, and see what they're up to. Your
primary tool for this is the shell.

The Shell

The shell is a program that allows you to interact with your computer.
It's called a shell because it provides an environment for you to work in
- sort of a little electronic home for you as you compute. (Think hermit
crab.)