background

a person's social heritage: previous experience or training

he is a lawyer with a sports background

the part of a scene (or picture) that lies behind objects in the foreground

he posed her against a background of rolling hills

information that is essential to understanding a situation or problem

the embassy filled him in on the background of the incident

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

relatively unimportant or inconspicuous accompanying situation

when the rain came he could hear the sound of thunder in the background