BTC is the shortened version of Bitcoin, but you may also come across mBTC and uBTC when you scroll through the list of cryptocurrencies on a Bitcoin casino. Basically, BTC is when you have one full Bitcoin instead of a fraction of it. mBTC is a smaller variation of Bitcoin, and it is named when you have a millibitcoin which is 1/1000 of one Bitcoin. A uBTC is much smaller than an mBTC at 1/1,000,000 of a Bitcoin. You will often see these cryptocurrencies when you don’t have the funds to deposit a full Bitcoin.