Định Nghĩa và Ý Nghĩa của "over and out"

What is the origin of the idiom "over and out" and when to use it?

The idiom "over and out" originated from the realm of radio communication, particularly in military and aviation contexts. In radio communication, "over" signifies the end of one's transmission, and "out" signifies the conclusion of the entire conversation. This phrase is used to convey a sense of finality and is used to close a conversation or communication link.