Btc or bitcoin are only created as a recompense for proof of work involving cryptographic ( Cryptography or cryptology is the practice and study of techniques for secure communication in the presence of third parties called adversaries) hashes called mining. Users offer their computing power to verify and record payments in to a public ledger ( ledger mean a book or other collection of financial accounts), known as the blockchain. Bitcoin that is already mined is in circulation and it can also be exchanged for goods and services. There will only ever be 21 million bitcoins in existence, with the final fractions ( a small or tiny part, amount, or proportion of something) of bitcoin being redeemed by miners in the year 2140. If this great bitcoin experiment succeeds and people still use it after that point, BTC miners will be supported exclusively by numerous small transaction fees – which are required to let your transactions be included swiftly into the blockchain. However, these coins can be divisible into smaller units, unlike regular currencies bitcoins are divisible by up to 10^8, which means that over time people will have the ability to use tiny little fractions of bitcoin to buy things. The smallest divisible unit of a bitcoin is aptly named a ‘Satoshi