The primary difference between a frappé and a milkshake is the recipe used for each; a basic frappé is made with water, sugar, instant coffee and ice cubes, while a basic milkshake consists of blended milk and ice cream. The two drinks are often confused because of their similar textures.
According to the Greek Reporter, the frappé actually originated in Greece in 1957, and it has since spread from there. Traditionally, a frappé is made from instant coffee, water and sugar by blending in a cocktail shaker and serving over ice. Using a blender to mix is also common. The resulting drink is very frothy and thick. Milk is commonly added and some less traditional recipes employ ice cream or whipped cream, making a drink that is easy to confuse for a milkshake.