A "letter" is a written message that people send to communicate with one another. It can be written by hand or typed on a computer and is often placed in an envelope for delivery. Letters can be personal, like those sent to friends or family, or formal, such as business correspondence. They allow us to express our thoughts, feelings, and information across distances. In the past, letters were the primary way to stay in touch, especially before the invention of email and text messaging. Today, while digital communication is common, many still appreciate the personal touch of receiving a handwritten letter in the mail.