The wheel and ignition are locked up, and the car won't start.
If you own a spare key, try turning the key in the ignition to see if this will work. If it does not turn the ignition, then look at your key and see if it is worn out. A worn key may need to be replaced by having another key cut. If that works then there will not be a need to replace the ignition key cylinder. If a key change still does not fix this, then a replacement ignition cylinder is needed.