metal disks

metal disks

but to add more:

Bitcoiners in my opinion make a mistake that is common to English-language speakers.

Rather than treat entities as real things and other concepts as not-real-things, people treat characteristics and actions as if they were entities.

In casual conversation we can get away with treating actions as entities (eg the claim "Running makes you thin"). However, when we are trying to perform logical deduction this is not a good way to reason.

Human beings and computers are entities that really exist. They can have characteristics or perform actions. Bitcoin is not an entity that really exists. Therefore it has no actual characteristics and performs no actual actions. Perhaps you can argue that Bitcoins are a characteristic of certain computing equipment, or an action performed by humans using certain equipment, but in neither case is it an entity nor can it be money.

Money is a thing that you give to someone as payment. It has to be a thing rather than an idea so that you give it for real (and not merely metaphorically).

Bitcoin's greatest strengths (low transaction cost, global distributed ledger, etc) result from the fact that it is a fiction. It's a lot cheaper to move nothing than something.