Supply and demand- Расскажите в кратце

Supply is how much of something is available. For example, if you have 9 baseball cards, then your supply of baseball cards is 9. If you have 6 apples, then your supply of apples is 6.

Demand is how much of something people want. It sounds a little bit harder to measure, but it really isn't. To measure demand, we can use a very simple numbering system, just like the supply one. If 8 people want baseball cards, then we can say that the demand for baseball cards is 8. If 6 people want apples, then we can say that the demand for apples is 6.