Injunction:

A court order that prohibits a party from doing something (restrictive injunction) or compels them to do something (mandatory injunction).

The opening paragraph of the relevant chapter of Spry's 1990 edition of Equitable Remedies cuts to the chase:

"An injunction is in order, historically of an equitable nature,  restraining the person to whom it is directed from performing a specified act, or, in certain exceptional cases ... requiring him to perform a specified act.

"Injunctions our hands often classified as either prohibitory or mandatory injunctions, according as they either restrain or require the performance of the act in question.

"They may further be classified as either interlocutory or interim injunctions, on the one hand, where the order itself is expressed to have effect only until a further hearing takes place or until a named day  or else contains some similar limitation, or perpetual injunction, on the other hand, with the order is not so limited."

REFERENCES:

• See also Mareva injunction.
• Spry, I., The Principles of Equitable Remedies (London: Sweet & Maxwell, 1990).