This board is pretty minimalistic. It has five general-purpose I/O pins that you can use to read and write logic-level signals (either 0V or your supply voltage

This board is pretty minimalistic. It has five general-purpose I/O pins that you can use to read and write logic-level signals (either 0V or your supply voltage, usually either 3.3V or 5V). Three of those also have analog-to-digital converters, so you can use them to measure voltages in that whole range. Two of these pins have hardware for generating PWM signals, making them useful for motor control. Three of these can be used for an SPI or I2C bus.