PerThirtySix's interactive explainers

Ever wonder how Shazam can identify songs based on a few seconds of audio, often against a noisy background? Or what exactly a QR code is and why it looks like that? Shri Khalpada has been making well-crafted interactive explainers for different systems that so far includes those two topics plus GPS, solar panels, and traffic lights—if that sounds as interesting to you as it did to me, you'll want to check out his site.