An Application Binary Interface describes how software encodes contract calls and decodes results, events, and errors.

A ledger design that stores a balance and nonce per address, used by Ethereum and many smart-contract chains.

A destination on a chain where funds or tokens can be sent. Format varies by network (hex, bech32, base58).

Receiving twice to the same address, which links history. Bitcoin culture treats this as a privacy leak.

Key pairs where the public key verifies what only the private key can sign or decrypt.

A time-boxed review of contract code. It reduces risk. It does not eliminate it.