Price Elasticity of Demand (PED) measures how customers change their behaviour when prices change. In other words, it refers to the relationship between price and demand, and how demand reacts when prices change.
Elasticity refers to the types of products which have different supply and demand curves. Some products like Ferrari’s are inelastic because an increase in price will have little affect on demand. However, products such as chocolate are typically elastic because price changes are more likely to affect demand.