The moon travels in an elliptical orbit at an average distance of 238,855 miles (384,400km) from the Earth.
An elliptical orbit means that it doesn’t travel at the same distance during the whole orbit. The point where the moon is closest to Earth is called the Perigee, and the point where it’s furthest away is the Apogee.
During a supermoon, the Perigee can be as little as 224,00 miles (360,000km). The apogee can extend out to 251,655 miles (405,000km).
The moon looks the biggest on Earth where it’s closest to Earth at the time of its orbit.