Novae and supernovae are distinct events, even though they share the Latin word "nova" (meaning "new") in their names. A nova is a sudden, intense brightening of a star, increasing its brightness by 100 to 10,000 times. This occurs in binary star systems, where a white dwarf pulls matter from a companion red giant until a powerful nuclear fusion explosion happens on the dwarf’s surface. The star isn’t destroyed, and additional explosions can happen, known as recurrent novae.
In contrast, a supernova is a violent explosion that marks the end of a star's life. Supernovae are far more brilliant than novae, often shining brighter than an entire galaxy for a brief period. If you want to learn more about the lifespan of stars, check out our colorful infographic.