This book describes the corrosion by various factors and their effects on various materials. It discusses corrosion on mild steel in various environments and its consequences and its protection of corrosion by various inhibitors. The various inhibitors were studied in various environments to protect corrosion. It can be useful to the undergraduates, graduates, postgraduates, and research students and also to the others who want to study corrosion and its various factors affecting it and its protection.