Command-Line Interfaces (CLIs) are text-based user interfaces that allow users to interact with a computer system by typing commands. Unlike graphical user interfaces (GUIs), which rely on visual elements like buttons and icons, CLIs require users to input specific text commands to perform tasks, making them powerful tools for advanced users and system administrators. CLIs are commonly used in various operating systems, including Linux, macOS, and Windows. They provide a way to automate tasks, manage files, and execute programs efficiently. While they may have a steeper learning curve, many users appreciate the speed and flexibility that command-line interfaces offer.