Margarine is a butter substitute spread made from vegetable oils (or, originally, animal fats) that are solidified through hydrogenation or blended with emulsifiers and water. It was invented in 1869 by French chemist Hippolyte Mège-Mouriès, commissioned by Napoleon III to create a cheaper alternative to butter; production shifted over the 20th century from animal fats to vegetable oils such as soybean, palm, and canola oil. Its flavor is generally mild and neutral, sometimes enhanced with salt, flavorings, or cultures that mimic butter's tang. It's used as a spread for bread and toast and as a butter substitute in baking and sautéing, though because many margarines contain more water and less fat than butter, they don't always perform the same in recipes - especially pastry and laminated dough - where butter's fat content and structure matter.