The long-awaited sequel to Blade Runner opened Friday. Blade Runner 2049 takes place 30 years after the original, in a post-apocalyptic LA.

But the phrase — and title — “Blade Runner” has gone through a bit of an evolution over the decades. It seems as though the actual term came into being not because it was the title of something, but because it was a job that somebody was doing.

With me to explain is Adi Robertson, a senior reporter at The Verge, who’s written about this.