Refacing involves putting a new surface over the external parts of your kitchen cabinets. Practically the same as installing a veneer, refacing materials are typically available in wood or plastic.
Pros: The refacing material can completely cover any nicks and scratches on the original surface, making it the perfect solution for battered cabinets. This also works great on cabinets made out of weak and porous material like plywood and MDF. It can also be easier and not as messy as a repaint job.
Cons: Can be a bit more expensive than a paint job, especially if you're going to go with wood veneers. This is also meant to cover only the external parts of the cabinets. While plastic self-adhesive covering surfaces are quite easy to install, wood veneers can be more difficult.
How it is done: You'll need to sand and clean the surface that you're going to stick the surface on. You'll then need to glue or iron-on and nail the surface onto the external panels, depending on what type you purchased. Cut and trim to the correct measurement afterward.
Repainting, as the name suggests, will involve applying new paint on your kitchen cabinets. Paint is pretty cheap overall
Pros: You won't be making any major physical alterations to your cabinets and you'll be able to change colors anytime you like. However, the best reason by far is that this is the CHEAPEST way to drastically change the look of your cabinets.
Cons: Can be quite messy. If your cabinets has deep nicks and scratches, paint alone won't cover it. You'll have to apply wood putty or caulking first to cover it up. Some paints also blister and peel away after some time. Usually, you can only repaint cabinets which can withstand moisture and paint stripping.
How it is done: First, you'll need to strip the original paint away using a chemical stripper or by sand paper. If there is no existing paint, you'll still need to sand and clean the surface so that the paint will bond to the surface better. Apply the primer, then 2 coats of paint, allowing the surface to dry completely in between coats.