In literature, a foil is an exact opposite or contrast to a particular character. In other words, the foil is used as a contrast to another character and it helps emphasize certain aspects of that character’s personality by showing what they are not like.
Foils can serve many different purposes in literature. They are often used to demonstrate a contrast between two characters, showing how one character’s personality or beliefs differ from those of another character.
A foil can also be someone who provides a contrast in terms of physical appearance. For example, if one character has dark hair and a pale complexion, it might be useful to have another character with light hair and tanned skin so that the reader can easily tell them apart.
The term “foil” comes from the old practice of using metal foil to highlight the raised parts of a painting or drawing. In literature, a foil typically serves to highlight the main character’s qualities by providing a contrast. For example, if one character is strong-willed and determined while another is timid and weak-willed, then they might make good foils for each other.
A foil may also be used to illustrate an important theme in a story.