What is the difference between a data cabinet, a network rack and a server rack?

The terms overlap considerably. A data cabinet or network cabinet usually means an enclosed rack intended for networking and communications equipment. A rack can also mean the mounting structure itself, including open-frame racks with no doors or panels.

“Server rack” usually implies something deeper and often heavier-duty, because full-size servers tend to require considerably more chassis depth, cable clearance and airflow than patch panels or network switches.

They’re descriptions rather than rigid species classifications. A deep network cabinet doesn’t suddenly become a server rack at midnight, and a shallow cabinet doesn’t object to a server merely on grounds of nomenclature. What matters is whether the equipment actually fits, is properly supported, remains within the load rating and can be cooled adequately.