Chemistry itself is the study of matter and how it changes. This science of matter is also looked it in terms of physics, but this takes a much more general approach than the specifics of chemistry. Chemistry, instead, is more specialized, looking into the reactions, composition and properties of matter, including the study of different atoms and molecules. It also takes into consideration concepts of energy and entropy, with regards to the spontaneity of chemical processes.
There are many subtypes of chemistry that are studied, including inorganic chemistry, organic chemistry, biochemistry and then moving into physical concepts of chemistry, including quantum mechanics and analytical chemistry. There are many different avenues of chemistry that can be looked into, emphasizing the importance of science in schools around the world today. Science has made us what we are today and without it, we probably wouldn't be around anymore, due to illness and other misunderstandings of life.