Virtual reality (VR) -- and augmented reality (AR) -- seem to be everywhere these days, showing up in demos and offerings from the world's biggest gadget makers to the Hollywood, gaming, and media crowds. But what's the difference between VR and AR? Is one better suited for work vs. play? What happens when you are building experiences -- and an entirely new visual grammar -- from scratch ... will we actually need standards next? a16z's Chris Dixon and Wired Entertainment's Peter Rubin discuss all this and more on this episode of the a16z Podcast.