equity: an overview
In law, the term equity refers to a particular set of remedies and associated procedures. These equitable doctrines and procedures are distinguished from "legal" ones. Equitable relief is generally available only when a legal remedy is insufficient or inadequate in some way. This could be when a claim involves a particular piece of real estate, or if specific performance is the relief requested by the plaintiff.
The distinction arose in England where there were separate courts of law and of equity. Following this pattern in America some states created "chancery courts" dealing with equitable relief only. In other states, the courts of common law were empowered to exercise equity jurisdiction. Separate courts of chancery have largely been abolished and the same court that may fashion a legal remedy has the power to prescribe an equitable one.