I/O stands for input/output. In computing, it refers to the communication between a computer system or program and its external environment, including peripherals, storage devices, networks, and users. Input involves receiving data or commands from external sources, while output involves sending data or results to external destinations.
Input devices, such as keyboards, mice, touchscreens, and sensors, provide data or instructions to the computer system. Output devices, such as monitors, printers, speakers, and actuators, display or transmit processed data or results to users or other systems.
I/O operations are fundamental to the functioning of computer systems, as they facilitate interaction between the computer and its users, as well as the exchange of data with external devices and networks. Efficient I/O management is crucial for system performance, responsiveness, and usability. Various programming languages and operating systems provide mechanisms for handling I/O operations, such as file input/output, network communication, and device control.