New to Bitcoin? Start at 1.1
2.1Lesson 1 of 7
Keys, addresses and wallets
This lesson answers
- What is a bitcoin address?
- What is the difference between an address and a wallet?
- What is a private key?
- Can someone steal my bitcoin if they know my address?
- Why does my wallet show a new address every time?
An address is where bitcoin is sent, a little like an account number for receiving. A wallet is the app or device that holds your keys. One wallet makes and uses many addresses, so a single address rarely shows everything someone owns.
Keys, addresses, wallets
| Private key | A secret number. Whoever knows it can spend what its addresses hold. It never needs to be shared with anyone. |
|---|---|
| Address | Made from a key. You share it to get paid. It doesn't let anyone spend, but it does let anyone see its balance and history. |
| Wallet | Software or a device that keeps your keys, makes new addresses and signs payments. It adds up all its addresses to show your balance. |
Four kinds of address
| Starts with | Kind | Real example |
|---|---|---|
| 1 | Legacy, since 2009 | The address of the first block's reward |
| 3 | Script, since 2012 | Binance's largest reserve address |
| bc1q | SegWit, since 2017 | Robinhood customer cold storage (reported) |
| bc1p | Taproot, since 2021 | The newest kind |
Newer kinds make payments a little cheaper. Most wallets today can send to all four. The examples link to their reports on satoshis.watch.
- Holds
- …
- Transactions
- …since 2018
- Separate pieces
- …unspent outputs
Binance lists this address in its published proof-of-reserves file, together with others. It is the largest single bitcoin address on the chain.
See it on satoshis.watch →One wallet, many addresses
Exchanges spread their customers' coins over many addresses, and ordinary wallets do the same on a small scale: most hand out a fresh address for each payment and send change to another new one. That keeps your history a little more private, and it is why one address on its own can show less than your wallet does. Old addresses keep working, so a payment to one you used before still arrives.
Check yourself
Practice, not a test. Think of your answer first, then reveal it.
1Can someone take your bitcoin if they know your address?Reveal
No. Spending needs the private key. An address only lets people pay you and see that address's balance and history.
2Why might one address show less than your wallet does?Reveal
Your wallet uses many addresses and adds them up. One address is only part of it.
3What does an address starting with bc1q tell you?Reveal
That it is a SegWit address, a kind used since 2017. It says nothing about who owns it.