You move from one point on the curve to another. Sometimes, price plays no role in determining your demand for a product. In each case, the price of the demanded product does not change. The first non-price determinant is Preferences . This is also called consumer tastes.
Fashion is a great example.
When disco died, the allure of such an outfit died with it. Demand for the jumpsuit decreased. Teenagers are an excellent group of people to watch and see this principle in practice. Their whims are quick lived and their peer pressure is so intense, that demand for some items has the life span of a gnat. Another non-price determinant is Income .