Why do we only see the same side of the Moon?
Just like the Earth rotates on its axis and revolves around the Sun at the same time, the Moon rotates on its axis and revolves around the Earth. But unlike the Earth where the two movements are at different speeds, the Moon's movements are synchronous. The Moon used to rotate on its axis much faster millions of years ago but the gravitational influence of the Earth gradually slowed it down to match the timing of its orbit. So every 29.5 days, the Moon circles the Earth and rotates once on its axis. Since these movements are synchronous, the same side of the moon is aways facing the Earth and reflecting the light of the Sun at night.
The moon Reflects the sun's light on the side known as the near side, where the moon reflects sunlight, and thus making it visible in our night sky. the moon is in a synchronous rotation with the earth, meaning that it completes its rotation in its axis the same time it takes to revolve around our planet. This is the reason why it nearly always keeps the same face turned towards the Earth.
I hope this helps.