Q. What is Bitcoin?
A. Bitcoin is a peer-to-peer digital currency. Peer-to-peer (P2P) means that there is no central authority to issue new money or keep track of transactions. Instead, these tasks are managed collectively by the nodes of the network.
Q. How does Bitcoin work?
A. Bitcoin utilizes public/private key digital signatures (ECDSA). A coin contains the owner's public key. When a coin is transferred from user A to user B, A adds B’s public key to the coin. The coin is signed using his private key. B now owns the coin and can transfer it further. A is prevented from transferring the already spent coin to other users because a public list of all previous transactions is collectively maintained by the network. Before each transaction the coin’s validity will be checked.