A backdrop is the scenery or background behind the main action in a play, photo, or event. In a school play, the backdrop might be a painted forest scene or castle wall hanging behind the actors. Photographers often use backdrops: solid-colored cloths or printed scenes that make their subjects stand out in pictures.

The word also describes the setting or circumstances surrounding an event. A championship game might take place against the backdrop of a rivalry between two schools. A family reunion might unfold against the backdrop of a beautiful mountain landscape. When a news story reports that negotiations happened “against a backdrop of tension,” it means tension was the background condition affecting everything.

Think of a backdrop as whatever forms the background context: the painted forest isn't the main focus of the play, but it helps you understand where the scene takes place. Similarly, when someone describes the backdrop of a historical event, they're explaining the surrounding conditions that help make sense of what happened. The backdrop isn't the star of the show, but it shapes how we experience and understand the main action.