Data centre systems or subsystems that are pre-assembled in a factory are often described with terms like prefabricated, containerised, modular, skid-based, pod-based, mobile, portable, self-contained, all-in-one, and more. There are, however, important distinctions between the various types of factory-built building blocks on the market.

This paper proposes standard terminology for categorising the types of prefabricated modular data centres, defines and compares their key attributes, and provides a framework for choosing the best approach(es) based on business requirements.