Terminal emulators are software applications that replicate the functionality of traditional computer terminals. They allow users to interact with the operating system through a command-line interface, enabling them to execute commands, run scripts, and manage files efficiently. Popular terminal emulators include GNOME Terminal, Konsole, and iTerm2. These tools are essential for developers and system administrators, as they provide a way to access remote servers and perform tasks without a graphical user interface. Terminal emulators support various protocols, such as SSH and Telnet, making them versatile for different computing environments.