Table of Contents1. Introduction2. Basic Principles of Laser Welding• 2.1 Definition of Laser Welding• 2.2 Laser-material Interaction3. Role of Gases in Laser Welding• 3.1 Types of Gas• 3.2 Effect of Gas on the Welding Process4. Application of Different Gases in Laser Welding• 4.1 Role and Advantage