An injunction is an order or write issued by a court of equity commanding an individual or group of individuals to do or refrain from doing certain acts. These certain acts may pertain to any one of a variety of matters. Here we are concerned only with the injunction as it is applied to labor organizations or individuals to prevent them from doing or cause them to do certain acts in their relationship to management. Whether these acts are lawful or unlawful is the point which decides whether or not an injunction will be allowed.
Robert M. Debevec, The Labor Injunction - Weapon or Tool, 4 Clev.-Marshall L. Rev. 102 (1955)