1. something that happens secretly or privately rather than in public
a lot of hard work going on behind the scenes
This expression is used figuratively to refer to any type of work that is carried out away from public view. That can be something done privately or even secretly. In a professional context, it often refers to negotiations or work that most do not see or know about. In a social context, it is often used to express visiting the private portion of a public venue, such as a restaurant, stadium, museum etc. Phrases with a similar meaning include 'behind closed doors,' and 'behind the curtain.'