The original VIX used to to be that. But for some time now (approx 2009) it's been a synthetic variance swap made up of a weighted sum of the "bunch of options"

The original VIX used to to be that. But for some time now (approx 2009) it's been a synthetic variance swap made up of a weighted sum of the "bunch of options" (weighted by square of the strike). The huge advantage that this makes over an actual implied vol is that it becomes replicable. And it's close enough to being the "fear index" of the popular press.