Introduction to the Command Line
GUIs and great for novice users: they allow people to get using a system without having to read a huge manual. However, there comes a time when the numerous mouse clicks to complete a task become a hinderance and where it is quicker to just bring up a terminal window and type in the command directly.
Where the command line (-also know as a "terminal window", "console", etc) comes into it's own is with automation and scripting: it's possible (-and will make your life so much easier) if you take common tasks and bundle the commands into one or more shell script (.sh) files, which can then be scheduled or added to the desktop or taskbar to run.
Linux systems traditionally use the bash shell. This stands for Bourne Again SHell - which is a pun on the Bourne shell used by many Unix systems.
A great in-depth Linux bash tutorial can be found at http://linuxcommand.org/learning_the_shell.php, so we shall just give you a flavour of the subject here.
For Ubuntu 10.x and below, a command line window can be invoked from the menu:
Applications → Accessories → Terminal:
For Ubuntu 11.04 and above, a Command Line window can be found from the "Ubuntu" menu:
In both cases, you should then see a Command Line window open up:
For Fedora, a Command Line window can be found by searching for the string "term" in the Applications area:
When you click on the Terminal icon, the command line window will open up:
For Mint, a Command Line window can be opened from the Main Menu:
When you click on the Terminal option, a command line window will open up: