A Command-Line Interface (CLI) is a text-based user interface used to interact with computer systems. Users input commands through a console or terminal, allowing for efficient control over software and hardware without the need for graphical elements. This method is particularly favored by developers and system administrators for its speed and flexibility. Unlike graphical user interfaces (GUIs), which rely on visual elements like buttons and icons, CLIs require users to memorize commands and syntax. This can lead to a steeper learning curve, but it also enables powerful scripting and automation capabilities, making it a preferred choice for many technical tasks.