Explain how the demand curves for normal products and for prestige products differ. what are demand shifts and why are they important marketers? How do firms go about estimating demand? how can marketers estimate the elasticity of demand?

This is marketing homework i need you to answer this quastion : Explain how the demand curves for normal products and for prestige products differ. what are demand shifts and why are they important marketers? How do firms go about estimating demand? how can marketers estimate the elasticity of demand?  answer this quastion in 1 page i need this homework in 12 houers from now.