Geology is the study of the earth. The study of geology has changed over time because of the scientific tools and the way the earth itself has changed.
Geology is also the study of everything that happens on the earth and inside.
A geologist is a person who studies the earth. They work with all types of instruments and meters to find out what the earth is doing and how it is. They must also travel to all climates of the world to study the way the environment is it is a extremly hard job and you must be dedicated to it to stay with it.