Recent report of Chamber of Digital Commerce describes twelve use cases of smart contracts, which can be described as a pieces of autovalidating/autoexecuting code sitting on distributed ledgers. Their role is to automate relations between entities on blockchain/DLT. In simple words, they act as a logic layer of crypto value transfer protocols based network. Smart contracts have potential to encode organisational rules and governance schemes of institutions into autonomous code on distributed ledgers.
Foreword by Nick Szabo, key figure of cryptoeconomy, author of smart contracts concept (1994), inventor of bitgold protocol (1998), the predecessor of bitcoin (2008).
Highly recommended to lawyers and programmers, or both on one.