Is the word "talent show" commonly used? What does it refer to?
Indeed it is! A "talent show" is sort of like a competition where individuals will sing, dance, act, perform, etc. in front of an audience and a set of judges. The judges determine what "talent" they think is the best and the winner usually gets some sort of prize. You may already know this, but a "talent" is a skill that a person possess or acquires over time with practice. For example, my talent is playing the flute! I have acquired this skill with eight years of practice. If I were to enter into a talent show, I think I would play the flute!