The "Ctrl" key, short for "Control," is a modifier key found on computer keyboards. It is typically located at the bottom left and bottom right corners of the keyboard. When pressed in combination with other keys, it allows users to perform various commands and shortcuts, enhancing productivity and efficiency. Common functions of the Ctrl key include shortcuts like Ctrl+C for copying, Ctrl+V for pasting, and Ctrl+Z for undoing actions. These shortcuts are widely used in many software applications, including word processors and web browsers, making it easier for users to navigate and manage their tasks.