What is the origin of the idiom "pick-up line" and when to use it?

The term "pick-up line" is believed to have originated in the early 20th century, specifically referring to a clever or witty line used to initiate romantic or flirtatious interactions with women. It stems from the concept of "picking up" or successfully engaging with a woman by employing a clever or humorous remark. It is used in social settings as a way to initiate conversation and display romantic or sexual interest in someone.