AZ is a well-known abbreviation in AWS. For all intents and purposes, it can mean a data center, but I've heard that AZs can span multiple physical data centers (which sort of makes sense -- there's a physical limit to how many servers you can fit in to one physical data center)
Some AZs have five data centers, though I’m not sure that up-to-date numbers are published. A DC and a single AZ are definitely not equatable in this regard.
