All-purpose Cleaners (APCs) are generally concentrated cleaning formulas made to clean a variety of surfaces. Several manufacturers make APCs. Some of the favorites around here are Meguiars APC, Costco's APC, etc. They are to be diluted with water for cleaning such areas as carpet/upholstery, leather/vinyl, plastic trim, tires, wheel wells, etc. The dilution level will vary depending on the surface. A 10:1 dilution, or a little weaker is good for cleaning carpets and upholstery. You would need a stronger dilution say for degreasing an engine, cleaning tires or wheel wells.