تعریف و معنای "[keep|play|hold] {one's} cards close to {one's} (chest|vest)"

What is the origin of the idiom "keep one's cards close to one's chest" and when to use it?

The idiom "keep one's cards close to one's chest" originated from the world of card games, particularly poker. It refers to a strategy where a player chooses to keep their playing cards hidden, close to their body, rather than revealing them to opponents. Metaphorically, the phrase signifies the act of being secretive, cautious, or reserved about one's intentions, plans, or information. It suggests that a person is not openly sharing their thoughts or revealing their true position, keeping their options and strategies concealed to maintain an advantage or avoid giving away too much information.