Will there be a closure or not in a simple example?

Question

Arduino

https://www.google.com/amp/s/heliosun.com.ua/ardui... I
looked at this lesson in electronics, I almost don’t understand at all, but if I understand correctly, when the button is pressed, 5 volts goes to the port, but no load is it a short circuit or not?
Also, I don’t understand this arduino button, there are 4 contacts .. as if, when the state is pressed, everything is connected to each other, and when not, are they connected only in parallel?

Answer 1

The MK ports in read mode are in a high-resistance state and the application of log voltages to them. 1 is completely safe.
The problem will be if you put the port on the output, set a low log. level and connect this case to the source, then there will be a short circuit to the ground / well, or set the log in push-pull mode. unit, and put the output on the ground.