A letter is a written message from one person to another. The role of letters in communication has changed significantly since the 19th century. Historically, letters were the only reliable means of communication between two persons in different locations.As communication technology has diversified, letters have become less important as routine communication. The development of the telegraph, telephone, and the Internet have all had an impact on the writing and sending of letters. In modern industrialized nations, the exchange of personal letters has become less common, being replaced by technologies such as the telephone and also e-mail. With the advent of the compact cassette, tape letters became a novelty.
