In a technical sense, Ethereum is a "world computer". Harking back to the days of the mainframe, and probably about as fast, Ethereum can be viewed as a single computer that the whole world can use. It notionally has only a single processor (no multi-threading or parallel execution), but as much memory as required. Anybody can upload programs to the Ethereum World Computer and anybody can request that a program that has been uploaded be executed.
Ethereum is a world computer