A letterhead is a distinct and branded header appearing at the top of official stationery, such as letter-sized paper or envelopes. It typically features a company or individual's name, logo, contact information, and often a design element. Letterheads are used to enhance the professionalism of written correspondence, creating a consistent and recognizable identity for businesses, organizations, or individuals. They convey a sense of authenticity and trustworthiness in letters, memos, and other formal documents.