通过查询Black’s Law Dictionary 9th Ed发现，“preliminary injunction”（同“interlocutory injunction”）的含义为“a temporary injunction issued before or during trial to prevent an irreparable injury from occurring before the court has a chance to decide the case (A preliminary injunction will be issued only after the defendant receives notice and an opportunity to be heard.)”；有关“interim injunction”的含义，可参见“interim relief”的含义，即“relief that is granted on a preliminary basis before an order finally disposing of a request for relief”。

仅从定义上看，二者并无明显区别，但通过下面描述可发现二者的区别。

An interlocutory injunction is an injunction that is obtained after legal proceedings have been commenced but before trial. The party who wishes to obtain an interlocutory injunction (generally the plaintiff) must bring a motion to ask for this relief. Notice to the defendant must be given so they can present their arguments in court and both sides can have a proper hearing. If granted, an interlocutory injunction usually lasts until the trial judgment is rendered by the court. To succeed on a motion for an interlocutory injunction, the plaintiff must satisfy the court that: (1) there is a serious question to be tried; (2) that it will suffer irreparable harm if the relief is not granted; and (3) that the balance of convenience weighs in its favour. If the injunction is granted, the defendant must stop its infringing activities (or whatever else the plaintiff has asked the court to order an injunction for).

Interlocutory injunction指的是法律程序开始后进行审理前法院签发的禁制令，一直持续到法院作出判决。若（通常为原告）希望获得该禁制令，必须发出动议申请获得救济，并且必须向被告发出通知。若想成功获得该禁制令，原告必须向法庭证明(1)待审理案件情节严重；(2)若不签发禁制令，其将遭受难以弥补的损害；以及(3)若不签发禁制令，其所受损害将超过其他人。一旦签发该禁制令，被告必须停止实施其某项行为。

An interim injunction is the shortest type of injunction ordered by the courts. Like interlocutory injunctions, an interim injunction is generally obtained after legal proceedings have been commenced but before trial. The party seeking the interim injunction must bring a motion to ask for this relief. Unlike interlocutory injunctions, interim injunctions are for situations that need to be urgently addressed to prevent immediate harm to the plaintiff. The injunction can be granted on an ex parte basis, meaning in the absence of the defendant, where the matter is so urgent that no notice is possible or where giving notice to the other party would defeat the purpose of the motion. It is typically granted for a very short period of time. Under federal law, an interim injunction on an ex parte motion is granted for a period of not more than 14 days. The plaintiff will also have to satisfy the three-part test for interlocutory injunctions detailed above.

与interlocutory injunction相同之处在于，interim injunction也是在法律程序开始后进行审理前法院签发的禁制令，同时寻求该禁制令的一方必须发出动议申请获得救济。但不同的是，interim injunction适用于亟待解决的情形，以免原告遭受直接伤害；该禁制令是单方签发，意思是说在紧急情况下无法向被告发出通知，或向另一方发出通知会违背动议的意图时签发。一般来说该禁制令的期限非常短，联邦法律规定针对单方动议签发的interim injunction期限不超过14天。

例句：

Foreign women residing legally in the country and who could not be expected to continue living with an abusive spouse could obtain a work permit, provided that: the spouse had been convicted under criminal law; an interim injunction under the Protection from Violence Act had been issued by a court; or the marriage had been dissolved.

合法居住在该国的外国妇女如果无法继续与施虐的配偶生活，则可以获得工作许可，前提条件是：其配偶已经按照刑法定罪；法院已经按照免受暴力保护法颁布临时禁令；或婚姻解体。

In Britain, when the damages can't provide enough compensation for the plaintiff, the judge offers interlocutory injunction to them by equitable law.

在英国，当损害赔偿不能给原告提供足够的补偿时，法官则通过衡平法为其提供临时性禁令救济。

参考：

Black’s Law Dictionary 9th Ed；

https://www.heerlaw.com/court-injunctions-intellectual-property