The Command Line and Basic Navigation
The command line is also known as a terminal. A command line, or terminal, is a text based interface to the system. You are able to enter commands by typing them on the keyboard and feedback will be given to you similarly as text.
The Shell bash. Within a terminal you have what is known as a shell. This is a part of the operating system that defines how the terminal will behave and looks after running (or executing) commands for you. There are various shells available but the most common one is called bash which stands for Bourne again shell.
Navigation
pwd This makes it easier to remember them.) The command does just that. It tells you what your current or present working directory is.
ls The command for this task is ls. It’s short for list. It tells you what is in the current pwd.
absolute and relative file paths. Whenever we refer to a file or directory, we can, in fact, use either type of path. Absolute paths specify a location (file or directory) in relation to the root directory. You can identify them easily as they always begin with a forward slash ( / ) Relative paths specify a location (file or directory) in relation to where we currently are in the system. They will not begin with a slash.