How Do Cryptocurrencies Prove Ownership Without a Bank?

Imagine you have a special notebook that everyone can see but no one can erase. When you give your toy to a friend, everyone writes it down together so nobody can lie about who owns the toy now.

In banks, they keep the books in their office. With cryptocurrency, there is no single office. Instead, thousands of computers around the world hold copies of this notebook. They are called a blockchain.

To prove you own your coins, you use two keys:

1. A public key like your email address. Anyone can see what you have.
2. A private key like your password. Only you know it.

When you spend money, you sign the transaction with your private key. It is like putting a special wax seal on a letter that no one else can copy.

Before anyone accepts your coins, they ask other people in the network to check. This process is called mining. Miners solve hard math puzzles to agree that you really have the money and haven't spent it twice.