This article discusses the processes involved in continuous hotdip coating of steel sheets, namely, hot and cold line processing, surface preparation, and post treatment. It outlines the properties and microstructures of metals and their alloys used in this process. The coatings considered in this article include metal coatings, such as zinc coatings, and alloy coatings, such as zinc-iron, types 1 and 2 aluminum, Zn-5AI, Zn-55AI, and lead-tin coatings.