What is the meaning of background?

noun

• A person's social heritage: previous experience or training.
  • usage: "he is a lawyer with a sports background"
• The part of a scene (or picture) that lies behind objects in the foreground.
  • usage: "he posed her against a background of rolling hills"
  • synonyms: ground
• Information that is essential to understanding a situation or problem.
  • usage: "the embassy filled him in on the background of the incident"
  • synonyms: background knowledge
• Extraneous signals that can be confused with the phenomenon to be observed or measured.
  • usage: "they got a bad connection and could hardly hear one another over the background signals"
  • synonyms: background signal
• Relatively unimportant or inconspicuous accompanying situation.
  • usage: "when the rain came he could hear the sound of thunder in the background"
• The state of the environment in which a situation exists.
  • usage: "you can't do that in a university setting"
  • synonyms: setting, scope
• Computer science. ( the area of the screen in graphical user interfaces against which icons and windows appear)
  • synonyms: desktop, screen background
• Scenery hung at back of stage.
  • synonyms: backdrop, backcloth

verb

• Understate the importance or quality of.
  • usage: "he played down his royal ancestry"
  • synonyms: play down, downplay