Law is a system of rules usually enforced through a set of institutions. Law affects everyday life and society in a variety of ways. Contract law regulates everything from buying a bus ticket to trading swaptions on a derivatives market. Property law defines rights and obligations related to transfer and title of personal and real property, for instance, in mortgaging or renting a home. Trust law applies to assets held for investment and financial security, such as pension funds. Tort law allows claims for compensation when someone or their property is injured or harmed. If the harm is criminalised in a penal code, criminal law offers means by which the state prosecutes and punishes the perpetrator.