That is the total supply in existence. It isn't really possible to know the total circulating amount of any given currency, as some gets lost over time
Everything is accounted for on the block chain. Whether it moves or not is irrelevant.
But isn't Monero also on the blockchain?
Yes, but all transactions are private so you can’t see the amounts or who sent or received the Monero. There is one special case of coinbase transactions, where the network pays miners in new Monero. In that case the transactions are partially transparent to show the amount sent to make the total Monero supply transparent