Detailing is the precise renovation and protection of the various surfaces of a vehicle.
You can go to your local hand car wash, and pay around £6 to have your car cleaned (The £6 Car Scratch wash!).
Be warned, most of these cheap car washes use harmful and corrosive products like traffic film remover to pre-wash your car, this will strip any protection on the car.
Dealer applied sealants can be stripped in roughly 3 washes. They also tend to use one sponge to clean the whole car, and not rinsing their sponge during the wash process either, which inflicts swirl marks, scratches and further damage to your paint work.
Detailing uses a much softer approach, using much milder wax and sealant friendly products, 2 buckets to wash, one with the suds, and one for rinsing the wash mitt, an assortment of cloths to dry, polish and buff you vehicles paint, and proven products to protect your vehicle, which in turn, will help increasing its retail value.