Could be many reasons. Help us help you by giving us more info like the year, make, model and engine info.
This isn't a question just because you add a question mark.
sounds like your timing belt has snapped.
If it doesn't restart it could be charging system failure, fuel pump failure or timing belt failure (if equipped).
The engine blows. Usually pistons shoot into the engine. In most cases the engine will have to be replaced.
Bad fuel filter or maybe some water in the gas tank.
It probably means the electrical system or charging system has failed.
It would die and not restart. Yes it may restart! I have had modules quit when they get hot and work again when they cooled down.
What kind of car year make and model?
When you buy a used car off of a car lot and they do not fix what is wrong with the car and it quits completely. Can a person back out of the deal and get their money back. And it has not even been a month when the car quits compeletly. What are my rights in this matter.
Knowing the year, make, model and engine info would help us greatly.
If you're driving a manual, it means that you've stalled out. Turn off the car and restart.
could mean anything. see if it happens again then see a mechanic