Explain what maria and craters are and how they formed?

Maria and craters are explained below:

Explanation:

The Moon is divided into light area lunar highlands and a dark area called Lunar Maria. Lunar Maria is large, dark, basaltic plains formed on earth's moon formed by ancient volcanic eruptions. Craters are formed when an impacting object falls and hits the moon's surface with greater speed and also formed as a result of the outward explosion of rocks. Craters are often caused by asteroids and meteorites with the lunar surface. Unlike earth-moon does not have an atmosphere to protect itself from impacting bodies. This is the reason for more number of craters formed on earth.