Tito**
Appendix:A smart contract is a piece of code, or program that ‘lives’ on a blockchain. Like any other contract in the real world, we write it, read it, agree on its terms and make the choice to sign it. Signing it with our address’ private key is called a transaction. A simple concept, isn’t it? We usually create smart contracts to hold or exchange financial value or let us point to sensitive information. Once a smart contract is written and deployed on a blockchain, it can’t be changed, so it is vital that we get it right before we deploy, so we will be test, test, testing them rigorously before deployment. In some cases we can make changes by using ‘upgradeable’ smart contracts, but we will visit this at a later stage on our journey.