Bitcoin’s creator, Satoshi Nakamoto, explained Bitcoin’s purpose in the whitepaper: "A purely peer-to-peer version of electronic cash would allow online payments to be sent directly from one party to another without going through a financial institution.

In the context of Bitcoin, a private key is what proves ownership of the funds corresponding to a given address. The private key is used to create signatures which are required to spend bitcoin. Private Key and Public Key Bitcoin uses public key cryptography to create a key pair...