You can probably guess that “pumping water” is the answer here. But that’s only part of it. The water pump actually pumps coolant, which, admittedly, contains a lot of water. An impeller - which is basically a fan - inside the water pump gets the coolant in motion, so that it can do its job, and keep your engine chilled out. Water pumps are located near the front of the car, and are usually powered by timing belts or chains, or drive belts. Electric-powered water pumps are starting to gain popularity as well.
Did you really need that spelled out? The water pump is part of the cooling system. When it fails, the ability to cool the engine might also fail, and then you have an overheated engine.
You just love leaks from your car, don’t you? Yeah. They’re super lovable. If you’re not familiar with the various liquids in your car, then a leak can be anything. But if you can tell that the leak is coolant, then it’s...well...a coolant issue, which means the water pump may have a leak.
Look, not everyone has eagle eyes. Maybe you didn’t spot all those leaks under your car. Maybe you ignored them. Yeah, that sounds more likely. But if you notice a low coolant level, then it’s because there’s a leak, and your water pump might be the guilty party.
You’re not being slick if you try to growl when revving the engine. But your car isn’t being slick, either. A weird growling noise from the engine is the sign of an unhappy water pump.