Written messages or letters from one entity to another may be classified as either business or personal. Personal letters are social correspondence between two individuals who know each other, while business letters are for commercial or other formal transactions between individuals or companies. Written messages may be conveyed through email, postal mail or text-enabled phone messages.
Business letters sent as printed hard copies through the postal service include cover letters for resumes, personal reference letters, letters from one company to another, and letters between customers, clients or suppliers. Letters ordering items or letters of complaint about services, as well as legal letters from attorneys or court officials to clients or other parties, are also sent as hard copies. Companies send out mass mailings to present special offers to customers or to advertise services offered. Business letters sent as hard copies produce a written record and are less easy to ignore than emails or text messages.
Friends, family members, pen pals or lovers send personal letters to convey information or feelings. Love letters expressing intense emotion were once almost exclusively handwritten. Love letters written by famous historical figures have been preserved for modern readers. Currently personal messages are most often sent electronically, making handwritten letters highly prized among those who love writing and receiving letters.