The document discusses the structure and elements of formal and informal letters as well as email etiquette. A standard letter includes a heading with address and date, salutation, body, conclusion, signature, and superscription. Formal letters are used for business or official purposes while informal letters are for friends and family. Email structure should include a precise subject line, salutation, purpose, paragraphs of more than three sentences each starting on a new line, appropriate font/size, and proofreading. Both letters and emails should be complete, clear, correct, concise and courteous.