The Moon’s far side is not permanently dark
We mostly see the same lunar face from Earth. That is about rotation—not an absence of sunlight on the other side.

The far side of the Moon is hidden from our usual view on Earth, but it is not hidden from the Sun. Confusing those two viewpoints creates one of space science’s most persistent misconceptions.
One turn matches one orbit
NASA explains that the Moon rotates in about the same amount of time that it takes to orbit Earth. This synchronous rotation keeps approximately the same lunar hemisphere facing our planet.
It is sometimes described as the Moon not rotating. That is misleading: the Moon does rotate. Its rotation is coordinated with its orbit, which is precisely why the same face generally remains turned toward us.
Hidden from Earth does not mean unlit
As the Moon travels around Earth, sunlight illuminates different portions of the lunar surface. The changing geometry produces the phases we see. The far side also has daylight and night.
At new Moon, the side facing us is mostly unilluminated while much of the far side faces the Sun. “Far” therefore describes a direction relative to Earth; “dark” describes lighting at a particular time.
Why spacecraft changed the picture
NASA notes that the lunar far side was first seen through images from a Soviet spacecraft in 1959. Space exploration made it possible to examine terrain that cannot normally be viewed directly from Earth.
For everyday conversation, “far side” is the clearer expression. It separates the location of a hemisphere from its changing illumination—and avoids turning an orbital relationship into a permanent shadow.

