A material is what something is made of. There are 5 basic materials. Most thing are made with these material. Some things are made of metal. Some things are made of glass. Some things are made of wood. Some things are made of cloth. And some things are made of plastic. There are some other materials. But there are not used as much as these 5 materials.
Let's talk about metal first. Metal is very heavy. And it is very hard and strong. It usually feels cool if you touch it. We use metal to make lots of things. We used it for forks and knives. We used it for keys. We used it for cars. We used it for these things because it is very strong.