That depends on people's definition about smart contract. Some people define smart contract as turing complete scripting/programming.
That is a subcategory of smart contracts and this definition was popularized after the introduction of Ethereum. Otherwise ever since 1990s a smart contract is technically a program or a protocol that can be executed automatically without human intervention, trusted third parties, etc.
The best and simplest example of a smart contract is the
vending machines which is the oldest implementation of them too.