Originally from the
theatre. A backdrop is a painted cloth in front of which the
actors
perform.Now a backdrop is taken less literally to mean the
background or
setting to many things. For example a
political backdrop is the history of a topic in front of which a current affair is played out. “Shares were a touch firmer in opening trade on Tuesday, despite the cloudy backdrop provided by global markets.
” (from BBC news online.)A backdrop can also used to describe the
background picture displayed on a computer
desktop.