Bitcoin is a currency and a monetary system in one. The term "Bitcoin" is therefore used equally for the monetary system and the individual "coin". We use BTC or XBT as the short form for the coin. Since the bitcoin is a digital "coin", it is very divisible. Small parts of a bitcoin are called "Satoshis". This name does not come by chance. It was chosen to honour the creator of Bitcoin. The inventor of Bitcoin is known by the pseudonym Satoshi Nakamoto. 1 bitcoin corresponds to 100,000,000 Satoshis (SATs).
As in the game, the number of bitcoins is limited. There will never be more than 21 million bitcoins. This makes Bitcoin a "hard" money. Everyone who owns Satoshis always owns a certain share of the total amount and can be sure that it will stay like this. We don't know that from any other commodity.
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