Question

what is meant by periscope

Answer 1

A periscope is an instrument for observation over, around or through an object, obstacle or condition that prevents direct line-of-sight observation from an observer's current position.

Answer 2

A periscope works by using two mirrors to bounce light from one place to another. A typical periscope uses two mirrors at 45 degree angles to the direction one desires to see. The light bounces from one to the other and then out to the persons eye.

Hope it helps