Gas welding is a process that uses a flame produced by burning a mixture of oxygen and acetylene to melt and join metal pieces together. The flame can be adjusted to achieve different temperatures, making it suitable for various types of metals and thicknesses. This technique is commonly used in metal fabrication, repair work, and artistic applications. It requires specific equipment, including a welding torch, gas cylinders, and protective gear. Gas welding is valued for its portability and versatility, allowing welders to work in various environments.