An On-Screen Keyboard is a software application that displays a virtual keyboard on a computer or mobile device screen. It allows users to input text and commands by clicking on the keys with a mouse, touchpad, or touchscreen. This tool is especially useful for individuals with physical disabilities or those who prefer not to use a traditional keyboard. The On-Screen Keyboard can be customized to suit user preferences, including different layouts and sizes. It is often included in operating systems like Windows and macOS, making it easily accessible for anyone who needs an alternative to a physical keyboard.