// GLOSSARY -- BLOCKCHAIN & CRYPTO FUNDAMENTALS
What is Address?
A blockchain address is a unique identifier derived from a public key that represents a destination for transactions — the 'account number' of the blockchain world.
WHY IT MATTERS
On Ethereum, an address is a 42-character hex string (starting with 0x) derived from the public key's Keccak-256 hash. On Bitcoin, addresses use different formats for different transaction types.
Address types on Ethereum: Externally Owned Accounts (EOAs) controlled by private keys, and Contract Accounts controlled by smart contract code. Both identified by addresses but behave differently.
Sending funds to a wrong address usually means permanent loss. Checksums (EIP-55) and address books help prevent errors, but responsibility lies with the sender.
FREQUENTLY ASKED QUESTIONS
Can I reuse addresses?
On Ethereum, yes. On Bitcoin, best practice is new addresses per transaction for privacy.
What if I send to the wrong address?
If someone controls it, they own the funds — irreversible. If nobody controls it, funds are permanently locked. Always double-check addresses.
Are addresses anonymous?
Pseudonymous, not anonymous. Addresses don't contain names, but all transactions are public. Chain analysis firms can link addresses to identities.