Geology is?

Simply put, geology is the study of the Earth. Like so many scientific words, “geology” is constructed from root words dating back to ancient times: geo comes from the Creek word meaning “the Earth”; it is a prefix used in other related fields, too, such as geography, geodesy, and geophysics. The alogy suffix comes from the Creek logos, meaning “discussion,” and is roughly translated as “the study of.”

What is geology?