Both are central air conditioning systems.
A single-package a/c combines the unit’s condenser and air handling in a single casing. If your air conditioner sits on your roof, it’s probably a single-package system.
A split system separates the two functions, so the evaporator is indoors and the condenser unit is outside. The evaporator might be in your attic, a closet, or even in your garage.
For more information contact McDonald Plumbing, Heating and Air at (916) 233-4194.