It can be confusing for those who aren’t steeped in the world of automobiles to know offhand who exactly someone is talking about when they mention the name Shelby when referring to a car, so hopefully this will help clear up some confusion. While both refer to high-end automobiles, they are quite different companies nonetheless.
SSC SuperCars - Founded in 1998 under the name Shelby SuperCars, SSC SuperCars is the company that produces the SSC Aero (often referred to as the Shelby Aero) and the Shelby Series 1. The name Shelby for this company comes from founder Jerod Shelby.
Shelby - Named for designer Carroll Shelby (no relation to Jerod Shelby), the most famous of his redesigns are the work he did with Ford Mustangs from 1965 to 1970. Generally, when someone is referencing an older car and using the Shelby name, they are referring to the Mustang Cobras made by this man. Carroll Shelby has also had his hand in multiple other performance cars, the most notable of which being the Dodge Viper.