A business letter is a letter from one company to another, or such organizations and their customers, clients, or other external parties. The overall style of letter depends on the relationship between the parties concerned. Business letters can have many types of content, for example to request direct information or action from another party, to order supplies from a supplier, to point out a mistake by the letter's recipient, to reply directly to a request, to apologize for a wrong, or to convey goodwill. A business letter is sometimes useful because it produces a permanent written record, and may be taken more seriously by the recipient than other forms of communication. It is written in formal language.