Bitcoin is a virtual currency that is also a fiat currency, there are no tangible assets attached to it. It works because people trust that they will be able to trade with it in the future. development 2009 by an anonymous group of developers, it is not just enough to social experiment. There are around 17 million bitcoins in circulation today valued at over 45 Billion dollars. To use and track bitcoins a user typically has a wallet which is a file that holds the ids of the bitcoins they own. The blockchain is a public ledger of all the transactions perform with bitcoins. When every user performs a transaction the blockchain is updated with the transaction, this transaction is publicly verifiable because the blockchain allows the lifetime of a bitcoin to be viewed by anyone.
What makes bitcoin a viable currency is the existence of miners. Miners are entities which management process in blockchain data, notably anyone with the right equipment can be a minor. This distribution is one of its most attractive features because it means that the currency is not under the control of any single government or party. The bitcoin code is open source which makes it less likely to be hijacked by malicious code that could violate the system. The miners update and secure the blockchain by repeatedly verifying and collecting newly broadcast transactions into a new group of transactions called a block. The blockchain is kept consistent complete in unalterable by the minor producing a hash based upon the transactions in the block and the previous block it is connected to. The hash is a string of characters derived from an algorithm that accesses a seal authenticity for the block data. However, the block isn’t deemed to be complete unless the minor can show proof of work which is essential for trust. Any change to the transactions already stored in the blockchain would produce a different hash, if this happens it indicates the blockchain has been tempered with.