This document provides an overview of various types of business letters covered in a business communication syllabus, including advertisement letters, application letters, curriculum vitae (CV), invitation letters for interviews, acknowledgment letters, offer letters, letters of acceptance, resignation letters, and testimonial letters. For each letter type, the document defines what the letter is, provides examples or templates, and discusses the importance and proper format. The overall document serves as a reference for writing different formal letters commonly used in business contexts.