What is command line?
A command line is a horizontal line on an interface that allows the user to enter various commands. Typically, a command prompt is on the left side of a screen with a blank line extending to the right where commands are entered.
In the past, command line interfaces have been a common type of interface for a personal computer. Now, command line interfaces are more commonly targeted at higher level users, where personal computers and business workstation operating systems often take a Windows-based approach. In a command line operating system, the entire screen is made up of a series of command lines. When a user enters commands, the field scrolls vertically. This allows the user to see past commands and responses from the computer.
Windows-based operating systems often include a shell or special function that allows the user to invoke a command line interface from within a window. This enables the types of functionality that command line interfaces provide. A command line interface is very simple in many ways and provides a clear visual record, which is one reason why some users still prefer it.