I agree that this may not be an easy question to answer.
But lately, I increasingly come across the fact that many news materials and research papers in the field of quantum technologies say that at the moment there is no quantum computer in the world. Instead, they argue that there are only prototypes of a quantum computer.
So what do Google, IBM, and other large companies produce? Are these really just prototypes of a quantum computer?
What about D-Wave computers (like a 2000 qubit quantum computer)?
What characteristics distinguish a quantum computer from a prototype quantum computer? And why then do some talk about a quantum computer, while others talk about a prototype of a quantum computer?