Zeroplus Arduino starter kit with Logic Analyzer Manual page 50

DESCRIPTION
An LED is a component that shines when a current flows through it.
[1]
Here we use the Arduino to light up an LED when a pushbutton is pressed
down and switch it off when the button is released . The pins on the
[2]
Arduino can be configured either as inputs to receive information from
the outside world or as outputs to send signals to other devices and
components.