What is a Bitcoin Private Key?
A private key in the context of Bitcoin
is a secret number that allows bitcoins to be spent. Every Bitcoin
wallet contains one or more private keys, which are saved in the wallet
file. The private keys are mathematically related to all Bitcoin
addresses generated for the wallet.
Because the private key is the "ticket" that
allows someone to spend bitcoins, it is important that these are kept
secret and safe. Private keys can be kept on computer files.
Private keys themselves are almost never
handled by the user, instead the user will typically be given a seed
phrase that encodes the same information as private keys.