What is matter? What is it made up of?

A definition of "matter" more fine-scale than the atoms and molecules definition is: matter is made up of what atoms and molecules are made of, meaning anything made of positively charged protons, neutral neutrons, and negatively charged electrons. There are three states of matter, they are: solid, liquid and gas. In extreme environments, other states may be present, such as plasma, Bose-Einstein condensates and neutron stars.