Surface coating is a reliable and cost effective process, used for the production of tools, materials, and machine components that requires desired surface properties like corrosion, erosion and wear resistance. The main purpose of applying the coating may be decorative, functional, or both. To improve surface properties such as adhesion, erosion, corrosion and wear resistance, functional coating may be used. Whereas, decorative coating such as artists paints are applied to make the product/material more attractive. Now days, number of coating methods are applied to achieve the desired functional or decorative properties. Thermal spray coating process is one of the effective and attractive methods to preserve/protect the new machine components from wear, hot corrosion, and erosion. This paper briefly explains various spray processes, their basic principles, advantages, and applications. In addition to this features, characteristics of coating methods and various corrosion prevention methods are briefly described..