Linux is considered a "Unix-like" operating system, and is similar to
operating systems like MacOS X, Solaris, and the BSD family, which are
descended from the original Unix operating system. (Windows and earlier
version of MacOS are not Unix or Unix-like systems.) When people talk
about "Unix [insert feature/component here]", as in "Unix shells" or "the
Unix filesystem", Linux is usually assumed to be included as well.
Like the BSDs but unlike Windows and Mac, Linux is available in a number of "distributions", each of which provides a complete system with numerous pre-configured software packages. The CSE Linux workstations and several of the servers run Debian, the parent of the popular (and more user-friendly) Ubuntu distibution.
All of the CSE Linux workstations, will load your home directory
when you log in. This directory contains all the files related to your
user account, including desktop and program settings. The path to this
directory is always /user/YOUR_NETID. Your Linux directory
is accessible as a Samba filesystem when you are logged into a Windows
workstation (open My Computer).
Your home directory is also loaded when you log into the CSE servers remotely. This allows you to work from your home computer without moving files around (see Working Remotely).
What is usually called the "command line" or "command prompt" in Windows world is usually called a terminal in Unix world. Both are command-line interfaces in the technical sense, and work by allowing the user type in commands to navigate directories, run programs, and so on. Most Linux distributions (even those with well developed graphical environments) still rely heavily on the terminal for administrative tasks, which makes the OS difficult for non-technical users.
Related to the idea of a terminal is the shell, which is the actual program or set of programs which provide a command line or graphical interface. CSE computers run the the shell "tcsh" in the terminal by default, but it is possible to configure your account to use a different shell, such as"bash". The basic functionality of these shells is mostly the same, but their scripting features (which make it easy to automate various tasks) are not, so tcsh and bash scripts are not compatible.
See the Unix
Tutorial (part of Lab Assignment 1).
Unlike in Windows and Mac, there are several completely independent graphical desktop environments available for Linux, including the fully featured Gnome and KDE, the lighter weight XFCE, and the very minimal LXDE. Desktop environments themselves are fairly modular, and in addition to basic components like window managers and file managers, often provide desktop publishing applications, web browsers, and so on.
The CSE Linux workstations run Gnome 2 by default, but it is possible to
choose a different desktop environment at login time. You can also run
programs from one desktop environment within another, though there is a
performance penalty in doing so since the libraries for both environments
must be loaded.
Gnome 2 should feel fairly familar to Windows and Mac users. Gnome's main differentiating features are the dual taskbars and the separate Applications/Places/System menus.
Note that copy and paste in the terminal are ctrl-shift-c
and ctrl-shift-v respectively. Elsewhere, shortcuts for
copy/paste, print, save, etc. are usually like Windows.
Most desktop customization and system administration tools have obvious
names.