Post (Mail) refers to the system used for sending letters, packages, and other items from one location to another. It involves various services provided by postal organizations, such as United States Postal Service (USPS) or Royal Mail, which collect, sort, and deliver mail to recipients. The process typically begins when a sender places their item in a mailbox or takes it to a post office. The item is then transported to a sorting facility, where it is organized based on its destination. Finally, it is delivered to the recipient's address, completing the mail delivery process.