GPIO stands for General Purpose Input Output. It refers to the pins on a microcontroller, microprocessor, or similar device that can be configured as either inputs or outputs. These pins are used to interface with external devices and components, such as sensors, motors, LEDs, and other hardware in embedded systems and electronics projects.

• Input: GPIO pins can be used to read signals from external devices (e.g., reading a button press or a sensor value).
• Output: GPIO pins can be used to send signals to external devices (e.g., turning on an LED or controlling a relay).