cryptocurrency

A cryptocurrency is money that lives entirely as entries in a shared digital ledger, with no bank, company, or government running it. Ordinary online money — the balance in your banking app — is really just a number in your bank's private database, and the bank decides what it says. A cryptocurrency instead records every balance and payment on a blockchain that thousands of independent computers keep identical copies of, so no single party owns the books or can quietly rewrite them.

What makes it work without a central authority is cryptography, which is where the name comes from. Each holder has a secret key, and only that key can authorize spending from their balance — like a signature that is mathematically impossible to forge. When you send coins, your wallet signs the transaction, broadcasts it to the network, and the network's consensus rules decide it is valid and lock it into the permanent record. Nobody needs to trust anybody; the math and the shared rules do the trusting for everyone.

Bitcoin, launched in 2009, was the first cryptocurrency and showed that strangers across the world could agree on who owns what without any middleman. Thousands of others followed, some acting as money and many doing far more — powering programmable contracts, apps, and whole financial systems. The common thread is the same: value that moves directly between people, around the clock, across borders, governed by open rules rather than by any one institution.