Nvidia’s Jensen Huang says ‘We’ve achieved AGI.’ But no one can agree on what that means. Why the most important term in tech remains hotly debated.

Last week, Nvidia CEO Jensen Huang made headlines when he told podcaster Lex Fridman that AGI—artificial general intelligence—had already been achieved.

AGI has long been the ultimate goal of many artificial intelligence researchers. That’s been the case even though there is no universally accepted definition of the term. It generally means AI that is as intelligent as humans, but there is a fierce debate over exactly how to define and measure “intelligence.”

In this case,...