Bitcoins aren’t printed, like dollars or euros – they’re produced by computers all around the world using free software and held electronically in programs called wallets. The smallest unit of a bitcoin is called a satoshi. It is one hundred millionth of a bitcoin (0.00000001). This enables microtransactions that traditional electronic money cannot perform.
Bitcoin (often abbreviated BTC was the first example of what we call cryptocurrencies today, a growing asset class that shares some characteristics with traditional currencies except they are purely digital, and creation and ownership verification is based on cryptography.