What is the difference between Partial and Required utility types?

Partial<T> takes a type T and creates a new type where every property is optional (marked with ?). This is useful for update operations where you may only want to change some fields: type UpdateUser = Partial<User>; — all properties of User become optional. Implementation: type Partial<T> = { [K in keyof T]?: T[K] };. Required<T> is the opposite — it removes the ? from all properties, making every optional property required: type CompleteUser = Required<User>;. Useful when you want to assert that all fields are present. Implementation: type Required<T> = { [K in keyof T]-?: T[K] }; — the -? removes optionality. Common use case for Partial: function updateUser(id: string, changes: Partial<User>): User { ... } — the caller only needs to provide the fields they want to change, not the full user object.