It's raining cats and dogs!! No it doesn't mean someone is throwing your pets off the roofs...It means it is raining really hard hehe

An "idiom" is a phrase that does cannot be translated or understood literally, but still has a specific meaning. "You're getting on my nerves" or "he has a frog in his throat" are examples.

idiom is an expression to abbreviate a long talk to a short sentence i can say it is a way to not to let the listener feel bored from u because u have long sentences