Question

Why does only one side of moon appear but not the other side​

Answer 1

Answer:

One side of the moon always faces Earth because of what's called synchronous rotation. That is, the moon rotates, or spins on its axis, in the same length of time it takes to orbit Earth. ... For that reason, our moon always has one side facing Earth, which we call the moon's near side.

Answer 2

Answer:

Only one side of the Moon is visible from Earth because the Moon rotates on its axis at the same rate that the Moon orbits the Earth – a situation known as synchronous rotation, or tidal locking. The Moon is directly illuminated by the Sun, and the cyclically varying viewing conditions cause the lunar phases.