Smart contract

Definition

Smart contracts are agreements or transactions with that are self-executing. They connect the blockchain database with users - they can be seen as an interface that, given a specific input, results in a specific outcome. For example, a smart contract can enable users to transfer funds, or trade digital products. Each blockchain (e.g. a cryptocurrency) has its own way of executing contracts, so each contract must be built for a given blockchain. For example, a smart contract might define that if a person enters blood pressure and disance walked in a week into a user interface, that user might receive a pre-defined number of tokens (see Tokens) that can be spent in a health-care provider's setup, e.g. on a consultation with a doctor.