Terminal Emulation

use of a communications program in order to enable a computer to function as a terminal

A terminal emulator, terminal application, term, or tty for short, is a program that emulates a "dumb" video terminal within some other display architecture. Though typically synonymous with a command line shell or text terminal, the term terminal covers all remote terminals, including graphical interfaces. A terminal emulator inside a graphical user interface is often called a terminal window.
See more at Wikipedia.org...

Noun
1. (computer science) having a computer act exactly like a terminal
(hypernym) emulation
(classification) computer science, computing

terminal emulation, use of a communications program in order to enable a computer to function as a terminal

What a terminal emulator does.