General-purpose input/output
Also: GPIO, digital pin
A configurable microcontroller pin for observing or driving logic-level signals.
Mode, alternate function, thresholds, source/sink current, voltage limits, and boot state define safe use.
Example Configure a button pin as input with pull-up and an LED pin as current-limited output.
Common misconception A GPIO is not a general load power terminal and must not drive a motor directly.