Ans 1: (Master Answer)
The word “until” is a conjunction that is used to refer to the time that took place or passed before an event or incident. Example, “You cannot watch television until you finish washing the dishes.”
The word “unless,” is also a conjunction. But it is used to refer to a condition which makes the event or incident that precedes it impossible. Example, "Unless you give me the money, I am not going to give you the shoes."