The document discusses the key components and formats of business letters. It explains that business letters are a formal means of communication between companies and can be used to inform, persuade, or advertise. The main components of a business letter are the date, inside address, salutation, body, complimentary closing, signature, and writer's identification. There are two common formats - full-block form where everything is left-justified and semi-block form where paragraphs are indented. The document also discusses punctuation styles and the seven C's of effective business letter writing.