Unless you can make the two systems independent, it's distributed. For most applications like shopping, for example, you must have a eventually centralized database. If you have multiple centralized databases that must talk to each other, guess what, that's a distributed system.
If those multiple centralized databases handle non-overlapping concerns, it is not different than a single centralized server. Still a distributed system (client & server) of course, but that doesn't seem to be what people in this subthread are getting at.
An example of this kind of architecture would be to have server per country, where each database synchronously maintains inventory for the warehouses it is (uniquely!) responsible for.
Unless you can make the two systems independent, it's distributed. For most applications like shopping, for example, you must have a eventually centralized database. If you have multiple centralized databases that must talk to each other, guess what, that's a distributed system.