Smart contracts are computer programs that are stored on a blockchain and are executed when certain conditions are met. They typically are used to automate the execution of an agreement so that all participants in the contract can be immediately certain of the outcome, without the involvement of any middle man like lawyers or government agencies.
Examples include financial activities that have been converted into computer code like trading, investing, lending, and borrowing. Other examples include applications for gaming, healthcare, and real estate. Smart contracts can even be used to configure entire corporate structures.