snythetic oil vs. regular oil whats difference

I would like to know what is the difference between synthetic oil and just regular oil you put in your car, I heard that snythetic oil is a great deal better, but I have no idea can anyone tell me what snythetic oil can do and whats its for thanks

Mobil 1 have som info about synthetic oils; http://www.mobil1.com/index.jsp

Quaker states website will help too

They both serve the same purpose... However, synthetics will last much longer because they don't burn off as readily. Synthetic oil also won't turn into sludge, and it can readily handily ambient temperatures lower than -20 degrees C (possibly even lower for many brands), and ambient temperatures over whatever environment you could possibly put it in.

Film strength for synthetics is much higher - up to 5000PSI, compared to petroleum oils, less than 500PSI.

Drawbacks? Price.