Anything that has mass and occupies space is called matter. A matter is made up of tiny particles called atoms.
The three states of matter are
Solids – it has a definite shape and volume. Example – wood, iron, ice etc.
Liquid – it has a definite volume but not definite shape. Example – water, milk, oil etc.
Gases – it neither has definite shape nor a definite volume. Example – air, hydrogen, oxygen etc