background

noun

1
scenery hung at back of stage
2
(computer science) the area of the screen in graphical user interfaces against which icons and windows appear
3
a person's social heritage: previous experience or training
he is a lawyer with a sports background
4
information that is essential to understanding a situation or problem
the embassy filled him in on the background of the incident
5
the part of a scene (or picture) that lies behind objects in the foreground
he posed her against a background of rolling hills
6
relatively unimportant or inconspicuous accompanying situation
when the rain came he could hear the sound of thunder in the background
7
extraneous signals that can be confused with the phenomenon to be observed or measured
they got a bad connection and could hardly hear one another over the background signals
8
the state of the environment in which a situation exists
you can't do that in a university setting

Also useful for “background”:Scrabble— High-value letters — see what it scores