What individual gun right did the Supreme Court recognize in District of Columbia v. Heller?

In the 2008 case District of Columbia v. Heller, the U.S. Supreme Court held that the Second Amendment protects an individual right to possess firearms for traditionally lawful purposes, such as self-defense within the home, independent of service in a militia.1

The Court’s majority opinion, written by Justice Antonin Scalia, rejected the collective-right theory—which argued the amendment only protected the right to keep and bear arms in connection with militia service—in favor of the individual-right theory. The ruling established that the right to self-defense is the central component of the Second Amendment, thereby invalidating district regulations that effectively banned handgun possession in the home.1