Raspberry Pi GPIO connect

Basically you can operate a GPIO pin either as input or output. As an input, it can evaluate the states “High” and “Low”. For example, from a switch, button or other signal-emitting circuit. As output, a GPIO can assume the states “High” and “Low”. This means that either a voltage of +3.3 V for “High” or 0 V for “Low” is applied to the input or applied to the output.

Raspberry Pi GPIO is the abbreviation for General Purpose Input Output. This designates programmable inputs and outputs for general purposes

The gpio are led out as a solder pin or pin in the form of a pin header and serve as an interface to other systems or circuits to control them via Raspberry Pi. When programmed, Raspberry Pi can accept digital signals from outside (input) or send signals to the outside (output).