Matter is anything that has mass and takes up space. It can be found in different forms, such as solids, liquids, and gases. For example, a rock is a solid, water is a liquid, and air is a gas. All these forms of matter are made up of tiny particles called atoms, which combine in various ways to create everything around us. Matter can change from one form to another through processes like melting, freezing, or evaporating. When ice melts, it turns into water, showing how matter can shift between solid and liquid states. Understanding matter helps us learn about the world and how different substances interact.