The four main types of matter are as follows:
1. Solid: Substances with strong intermolecular forces and few intermolecular spaces possess a definite shape and size.
2. Liquid: Substances that take the shape of the container in which they are placed. They have weaker forces of attraction amongst particles and larger spaces between their constituents.
3. Gas: Substances with very large spaces between the constituent particles, very weak forces of attraction, and thus they lack a proper shape.
4. Plasma: A rare type of matter with very high kinetic energy particles. It is an ionised gas with almost equal positively and negatively charged particles. Stars are a type of superheated plasma.