The document discusses different types of letters including informative, good news, persuasive, and bad news letters. Informative letters aim to clearly convey information to the reader. Good news letters grant requests or provide favorable responses. Persuasive letters attempt to convince the reader by focusing on their needs and presenting logical proposals. Bad news letters require delivering unfavorable information courteously by de-emphasizing negatives, stating reasons clearly, and including a goodwill ending. All letter types should be factually correct, well-organized, and use an appropriate tone.