Ethereum Smart Contracts: usage, security & audits

A smart contract represents a piece of code deployed and running on the blockchain. The concept itself was invented by Nick Szabo in 1990, long before crypto in general and Ethereum, in particular, were rolled out. In his publication, he described a smart contract as a computerized transaction protocol that executes the terms of a contract. However, it was Vitalik Buterin who came out with a real-life application of this technology many years later in 2015.