For those of you familiar with UNIX making the transition to Linux is a breeze. Those of you coming from Windows this will be quite an adjustment. Luckily, it has gotten much easier over time. Now with great desktop environments like KDE & Gnome the need to hit the command line to perform basic operations is minimal. Average users who will utilize there PC for email, chatting, and browsing the net can probably skip this section as it will be more information than you need.
Now for those looking to explore the real power that Linux has to offer this is the stuff for you. If you are coming from the Windows world the closest thing you have to compare the Linux shell with is the Windows command prompt and DOS. Sometime things just can’t be done through a GUI or at least not done as well. Therefore, it is often necessary to get behind the GUI interface (i.e.) Gnome, KDE, etc. The Linux command line goes by many names (AKA: the shell, bash, , c-shell, k-shell, terminal, and/or konsole).
The most common uses of the shell for intermediate users will be launching applications, installing software, building RPM packages, etc. I don’t profess to be an expert at the Linux shell. I’m learning just like you. There are so many commands you can’t possibly learn and/or retain them all. Don’t worry about it. You’ll find that you use the same dozen or so over and over again. You’ll also find that Linux is so flexible that there are 10 different ways to do something, You get to pick which way works best for you. There are plenty of command reference sites and Linux even provides it’s own reference guides called the man and info pages. Man meaning manual. You can call these by typing “man” followed by the command you want to learn about (ex) man tar.
Here’s one reference site I use a lot.
Here’s a great tutorial on the use of the Linux shell / bash and the man pages.