back·drop 
(băkdrŏp′)
(băkdrŏp′)n.
1. Something used as a background, especially:
a. A painted cloth hung at the back of a stage set.
b. A taut cloth suspended in a frame and used as a background against which to take a photograph.
c. An image, often painted or digitally created, used in cinematography as the background of a scene.
2. The setting, as of a historical event; the background.