Address
Also: Bitcoin address
cryptography · beginner
A short string encoding a destination for bitcoin — usually a hash of a public key with a checksum.
Addresses come in several formats: legacy P2PKH ("1..."), P2SH ("3..."), bech32 native segwit ("bc1q..."), and bech32m Taproot ("bc1p..."). Each is an encoding of a locking condition. Modern wallets prefer bech32 — cheaper fees, better error detection, all lowercase.
An address is not an account. There's no balance attached to an address on the chain; only the set of unspent outputs locked to that address. Block explorers compute "address balance" by summing those outputs, but the chain itself doesn't have the concept.
The checksum embedded in every Bitcoin address catches most single-character typos, so a typo'd address almost always fails validation rather than silently sending to the wrong place. But the checksum is *not* a destination check — if you copy a malware-substituted address, the checksum is valid and the funds go where the attacker intended. The defense is verifying the full address on a trusted display, ideally a hardware wallet screen.