What is an Injunction in law and what Law governs injunction?

Injunction is a remedy in the form of Court Order or Decree by which a party to an action is required to do, or refrain from doing a particular thing. Injunctions are either restrictive (preventive) or mandatory (compulsive). As regards, time, injunction are either interlocutory (interim) or perpetual. 

NB: Perpetual injunction is granted after the plaintiff has established his right and there is say, continuing breach by defendant whereas interlocutory injunction may be granted pending the outcome of the main hearing of the case. Injunction is governed by the Civil Procedure Act R.E 2002 under the provision of Order XXXVII.