Grease, oil, butter and fat are al the same when it comes to dealing with the stain.. They are stains that can be dealt with quite easily in numerous ways.

General laundry advice

General laundry advice is to soak the item in water with your usual detergent prior to washing at the maximum temperature that the fabric will allow. Any remaining stain can be removed with any household grease solvent. Grease solvents are washing up liquid /dish detergent, household soap or white spirit. You can also but a multitude of commercial grease solvents. In the UK they have names such as Dabitoff or Swarfega

Great tips

To remove grease from clothing: Pour Coca-Cola onto the grease spot and rub it in. Then pour some more on the spot and let it sit for 10-15 minutes. Launder your clothes with detergent as usual. You can either drink the rest of the Coke or pour it in the washing machine at the start of the wash cycle. No, your clothes don't come out sticky. This works well even on the heavy, thick grease that truck drivers get on their shirts when they exchange trailers. I suspect it's the phosphoric acid in the drink that does the trick. 

I know a great way to get rid of oil or butter from clothing and prevent it from staining. All you need to do is sprinkle some dusting powder (talc) over the oil mark and leave over night, wash the garment as normal the following day. The Talc will draw all the oil out of the clothing and completely remove all trace. Trust me it really works!

For butter and grease stains use Dawn Dish Soap. This works even after you have let the stain set in and tried other ways of getting it out. Pour soap on the stain and take a wet wash cloth and rub the soap in really good. Then Add more soap and rub some more. Finally put more soap on the stain and place the wash rag on the stain and roll the item up with the wash rag still inside. Place this in the washer and wash with medium warm to hot water. 

To remove oily stains on clothing, try sprinkling baby powder on the stain. Let it absorb the oil for about 24hours. Then wash or dry clean as normal