It is a court order to stop. One judge can freeze a policy, a project, or a person in their tracks, sometimes for the entire country, with a single ruling.
An injunction is a court order requiring someone to do, or more often to stop doing, a particular thing. Unlike money damages, which compensate for harm already done, an injunction is forward-looking: it prevents harm before it happens or stops it as it occurs.
Courts grant injunctions when money cannot fix the problem. If a factory is about to bulldoze a forest, or a government is about to enforce a law that violates rights, no later payment can undo the damage, so a court can simply order it stopped.
They come in degrees. A temporary restraining order freezes things briefly in an emergency; a preliminary injunction holds the line while a case proceeds; a permanent injunction is the final order after a case is decided.
In recent decades a powerful and controversial form has emerged: the nationwide injunction, in which a single federal judge blocks a government policy not just for the parties in the case but for the entire country, a practice that has become a major flashpoint in American law.
