Unix
Terminal and Command line
What is the command line interface ?

A
command-line
interface
(CLI),
also
known
as command-line user interface, console user interface,
and character user interface (CUI)

A CLI (command line interface) is a user interface to a
computer's operating system in which the user responds
to a visual prompt by typing in a command on a specified
line, receives a response back from the system, and then
enters another command…
What is the command line interface ?

The CLI was the primary means of interaction with most
computer systems until the introduction of the video display
terminal in the mid-1960s, and continued to be used
throughout the 1970s and 1980s
personal
computer
systems
on Unix systems and
including
MS-
DOS, CP/M and Apple DOS.

The interface is usually implemented with a command
line shell, which is a program that accepts commands as text
input and converts commands to appropriate operating system
functions.
What is the terminal?

The terminal is It is a method of controlling some aspects
of Ubuntu using only commands that you type on the
keyboard.

Why would I want to use the terminal?
the terminal is a powerful and invaluable tool that:
What is the terminal?
1.
can be used to perform many useful tasks you might not be
able to accomplish with a GUI. For example Troubleshooting
any difficulties.
2.
It is sometimes a faster way to accomplish a task. For
example, it is often easier to perform operations on many
files concurrently using the terminal.
3.
Learning the command-line interface is the first step towards
more advanced
development Skills.
system administration, and software
Opening the terminal
1.
by clicking Dash then searching for word “term”.
2.
can open the terminal by hitting Ctrl+Alt+T simultaneously.

The terminal gives you access to what is called a shell. When
you type a command in the terminal, the shell interprets
this command, resulting in the desired action.
Opening the terminal
Unix Command

UNIX commands must be entered in the following form:

command -options arguments The command is always the
first word. The options modify the function the command
performs. The arguments identify the data (usually a file or
files) upon which the command performs its function
Reference
http://web.cecs.pdx.edu/~rootd/catdoc/guide/TheGuide_38.html