What is a background actor?

IN MY OPINION:

WILLIAM REYNOLDS;

I GET THIS QUESTION FROM TIME TO TIME:

What is a background actor?

A background actor or extra is a performer in a film, television show, stage, musical, opera or ballet production, who appears in a nonspeaking or nonsinging (silent) capacity, usually in the background , for example, in an audience or busy street scene,  called a 'fan' or, 'pedestrian'. on your resume.