The purpose of this eBook is to provide a basic understanding of modular data centers and the UL requirements related to such products. Information presented in this book comes from the UL website, expert sources, and information presented in a UL webinar on modular data centers and related certifications. Some subjects covered in this eBook will include key definition of modular data centers, a brief history of UL's involvement in modular data center listings, and technical requirements ranging from structure, electrical, egress, HVAC to transportation issues.