What is matter?

Scientists try to know what composes any substances. But they found that a substance may differ in state. For example water. Water can be found as liquid, ice, or vapor. another example is rock. Rock can be found as magma, harmful gas, or rock. Etc, etc. Thus the concept of matter come into their thinking. It must be something that has three states: liquid, solid, or gas. The later scientists defined in a more sophisticated words, that is, matter is something that takes up space and has mass (weight). So, the concept of matter is generalized.