Sometimes courts issue orders, especially injunctions, which require the litigants to maintain the status quo. Literally, the phrase means to maintain the existing state of things at any given moment. For example, if a court enters an injunction requiring a landowner, threatening to install a fence on his neighbor’s property, to maintain the status quo, it means that no action can take place until further order of the court. Things must remain “as is” until the court makes further findings and issues a ruling.
The phase status quo ante means the state of affairs that existed prior to some time or event. If the court orders a party to return to the status quo ante, it means that the party may have to undo something that has been done (such as the unlawful installation of a fence on a neighbor’s property) and return things to their original state as they existed prior to the unapproved act.
— BBC&B