File:Bitcoin explained in 3 minutes. It allows people to send or receive money across the internet, even to someone they don’make free bitcoin know or don’t trust. Money can be exchanged without being linked to a real identity. A Bitcoin address, or simply address, is an identifier of 26-35 alphanumeric characters, beginning with the number 1 or 3, that represents a possible destination for a bitcoin payment.
Addresses can be generated at no cost by any user of Bitcoin. For example, using Bitcoin Core, one can click “New Address” and be assigned an address. It is also possible to get a Bitcoin address using an account at an exchange or online wallet service. One of the differences between using bitcoin and using regular money online is that bitcoin can be used without having to link any sort of real-world identity to it. Unless someone chooses to link their name to a bitcoin address, it is hard to tell who owns the address. Each address has two important pieces of cryptographic information, or keys: a public one and a private one.
Because of this, it is very important that this private key is kept secret. To send bitcoins from an address, you prove to the network that you own the private key that corresponds to the address, without revealing the private key. This is done with a branch of mathematics known as public key cryptography. A public key is what determines the ownership of bitcoins, and is very similar to an ID number.