What is the difference between paraffinic base oil and Naphthenic base oil?

The paraffinic base oils are prepared by solvent separation techniques from paraffinic crude oil, wich give good yield of high viscosity index stocks containing a lot of wax. Paraffinics have good thermal and oxidative stability and high-temperature viscosity characteristics. The naphthenic base oils derived from naphthenic crude are very available and very inexpensive. They yield medium viscosity index and low viscosity index base oils with very little wax and naturally low pour points.