What is 'aquaplaning' (hydroplaning) and how do you prevent it?

1. It is a steering lock caused by low power steering fluid.
2. It is a loss of steering control when a layer of water builds up between the tires and the road surface.
3. It is an engine cooling system failure that happens when a vehicle is driven through deep puddles of standing water at speed.
4. It is a skidding motion caused by over-inflating tires.