What is Geology??

The science that deals with the earth's physical structure and substance, its history, and the processes that act on it is called Geology.

The   word   GEOLOGY   has   heen   derived   from   the   Greek   words   GEO means   the   Earth   and   LOGOS   means   discourse (gagia  or ge,  the; ancestral   Earth-goddess   of   Greek   mythology,   logy,   a   suffix   denoting
knowledge   of ).

Geology  is  therefore   the science  of   the   earth. The   science   of geology  includes   the   study   of   the   earth   as   a whole; The   study   includes   its origin,  structure, composition,   and history (including   the   development   of   life), and the nature of the processes, which have given rise to its present state.

Geology is the study of the Earth, the materials of which it is made, the structure of those materials, and the processes acting upon them. It includes the study of organisms that have inhabited our planet. An important part of geology is the study of how Earth’s materials, structures, processes and organisms have changed over time.

Further Explanation:
Geology is the study of the Earth, its processes, its materials, its history, and its effect on humans and life in general.  Rocks, crystals, mountains, earthquakes, volcanoes, rivers, glaciers, landslides, floods, and many other subjects fall into this broad field of research.  Geologists perform a wide range of important services for our civilization: they determine the stability of building sites, find abundant supplies of clean water, search for valuable deposits of natural resources such as iron, coal, and oil, and they also try to minimize the threat to communities at risk from geologic hazards.
Geology is special in that it is a highly field-oriented science.  A geologist's work is usually outdoors, sometimes in out-of-the way places such as deserts or sparsely populated mountain ranges.  Some of the most geologically interesting places in the world are also the most scenic.  Students of geology can expect to find themselves working in locales that they have often wanted to travel to, as well as many that they had not known of but were grateful to have visited still.
Geology is a very visual science.  Many problems in geology are much like solving a puzzle.  A common task for students is to present a possible explanation of the events that occurred to produce the scenery surrounding them.  If you have ever wondered how a certain hill came to exist in a certain place, or why a cliff or canyon should have such a vivid display of color to it, or why a large outcrop of rock is exposed in a particular fashion, a background in geology can help you to return to those features and figure out the answers.  Once you have had an introduction to geology, you will see the world around you in a completely new light.