Choose the odd one out.

The question requires identifying the odd one out among computer peripherals based on their functional roles. Computer hardware is generally classified into input and output devices:

• Scanner: An input device used to capture images or text from physical documents and convert them into digital format.
• Mouse: An input device (pointing device) that allows users to interact with the computer's graphical user interface.
• Keyboard: An input device used for entering alphanumeric data and commands into the system.
• Printer: An output device that receives digital data from the computer and reproduces it in a physical form, typically on paper.

Since the Scanner, Mouse, and Keyboard are all categorized as input devices, the Printer is the odd one out because it is an output device.