Everything on Earth is made up of matter. There are three basic states of matter: solid, liquid, and gas.
A solid is anything that holds a particular size and shape.
An apple, a block of wood, and a coin are all solids. The only way they can change their shape is by force (for instance, if you bite the apple with your teeth or chop the block of wood with an axe).
The particles in solid are tightly packed and don't make a lot of movements. There is not much free space in between the particles, so there is very little room for the particles to move.
A liquid is anything that has size or volume but does not have a shape. Liquids must be contained in a cup, bottle, or some container in order to have a shape. Milk, water, and juice are liquids. When you pour milk into a glass, it takes the shape of the glass. If you spill the glass of milk on the floor, it will spread quickly as it takes the shape of the floor.
Particles of liquid are not as close together as particles in a solid and move around much more freely. They have no regular shape or arrangement and move freely.
Gases are hard to identify because they have no colour, size or shape. When we take a deep breath our lungs fill up with air. Air is a combination of many gases.
The particles in a gas move freely at high speeds. There is a lot of free space in between the particles, and they take the shape of any container.