Foils are thin sheets of metal, often made from materials like aluminum or tin, that are used in various applications, including cooking and packaging. In cooking, aluminum foil helps to retain moisture and heat, making it ideal for baking and grilling. It can also be used to wrap food for storage, preventing spoilage. In literature, a foil is a character who contrasts with another character, usually the protagonist, to highlight particular qualities or traits. For example, in Shakespeare's plays, characters like Hamlet and Laertes serve as foils to each other, emphasizing their differing approaches to action and morality.