There are three different states of matter: Solid, Liquid, and Gas.
Solids are rigid and has a fixed shape and volume.
Liquids have a definite volume; it takes the shape of its container.
Gases have no fixed volume or shape; it takes the shape and volume of its container.
Here is a fun song to help you remember the differences between the different states.
Changing States
Different Processes:
Melting: Changing from solid to liquid.
Evaporation: Changing from liquid to gas.
Condensation: Changing from gas to liquid.
Freezing: Changing from liquid to solid.
Melting: Changing from solid to liquid.
Evaporation: Changing from liquid to gas.
Condensation: Changing from gas to liquid.
Freezing: Changing from liquid to solid.