Honda fit engine can start, it won't move when drove but move when parked......

What is your question?

It suddenly stopped at traffic light, but the engine was still on, and the noise came out. I pushed the car to the side of road and waited. I restarted the engine, tried to open and close windows. Engine and battery both worked, but the car could not be driven. I won't move when drove what ever go forward or backward. However, it could move when I parked it. What could be the problem? Transmission need to be replaced?