NORAD is back in the news. So what does it do, exactly?

For years, North American Aerospace Command — or NORAD — had its headquarters inside Cheyenne Mountain, at the foot of the Rocky Mountains in Colorado. In this archival photo, a bus enters a tunnel for a half-mile trip to a command center inside the Cheyenne complex. The headquarters is now in nearby Colorado Springs. (Kevin Moloney/Getty Images)

It was created as a counter to a rival superpower. So in a way, it's fitting that a tiff with another superpower has once again thrust North American Aerospace Command — or NORAD — into conversations about national security and spying.

For the public, the most frequent mentions of NORAD likely come in Cold War-era stories and its famed Santa Tracker, which makes the news every Christmas. But over its nearly 65-year history, NORAD has had to adjust to new threats, and its leader says it needs to modernize, citing a "domain awareness gap" and equipment that was installed in the 1970s and '80s.