Meaning of “background” - Learner’s Dictionary

background

noun us uk /ˈbækɡraʊnd/
The computers were humming in the background.A radio was playing in the background.I could hear the sounds of a party in the background.I thought we needed a little background music.There is some background noise on the recording.
SOUND [ no plural ]

B2 Sounds in the background are not the main sounds you can hear:

background music/noise
I could hear a baby crying in the background.
PERSON [ C ]

B1 a person's education, family, and experience of life:

She came from / a middle-class background.
PICTURE [ C, U ]

B2 the parts at the back of a picture, view, etc that are not the main things you look at:

gold stars on / a black background
SITUATION [ C ]

B2 the situation that an event happens in, or things that have happened in the past that affect it:

[ usually singular ] The talks are taking place against a background of economic uncertainty.
in the background

If a person stays in the background, they try not to be noticed.

(Definition of “background” from the Cambridge Learner’s Dictionary © Cambridge University Press)