If you are cooking with grease or oil on your stove and it catches fire, whatever you do, do not put water on the fire. If you put water on a grease or oil fire, it will get much worse.

The first thing to do if you get a grease or oil fire on your stove is to call 911. If you want to attempt to put out the fire yourself, there are two ways to go about this.

First, you can use a fire extinguisher that is rated for Class B fires (flammable liquids). Most people who have fire extinguishers in their kitchen have ones rated for A-B-C. If this is the case, you are good to use it on the grease or oil fire. If the extinguisher is not rated for Class B fires, do not use it on a grease or oil fire as, like the water, it will make the fire worse.

Second, if the fire is contained in something like a pot, you can just put a lid on the fire. This will deprive the fire of oxygen and it will go out pretty quickly. The key here is to be safe when putting the lid on so that you don't get burnt.

Of course the safest thing to do is to just call 911 and evacuate your house. Let the fire fighters handle it.