The ‘dark side’ of the Moon refers to the hemisphere of the Moon that is facing away from the Earth.
The moon has a day side and a night side , just like the Earth. The day side is the side currently receiving sunlight, while the night side faces away from the sun. What does this have to do with the side we see when we look at the moon from Earth? That’s where things can get confusing. The side of the moon we see is sometimes the day side, and sometimes the night side. It all depends on when during the lunar day we look at the moon.