Why is the demand curve downward sloping

The demand curve shows how different prices of a commodity affect the quantiy demanded by consumers.Price is always show on the y-axis (vertical) and quantity on the x-axis (horizontal). These two variables have a negative relationship with each other, creating the downward slope.

To fully understand this, imagine an economy of consumers ranging from the super rich to the super poor. When the price of a good is very high only a small amount of the economy can afford it and so the quanity demanded by consumers will be smaller. As the price of the good decreases more of the economy will be able to afford the good and the quantity of demand increases. This relationship then creates a downward sloping curve.