Car Emblems: What Do They Mean?

I was working out in the garage the other day.  You know, the place where my wife parks and my vehicle has never been.  As I'm taking a break, looking at my wife's Jeep, I thought "why do Jeeps have the seven slots in the front?" That sent my quiet and sometimes subdued brain into overdrive. Why does Chevy have the bow tie, Ford the Oval, and what the hell is that thing on a Toyota Car?  It looks like specimen they took out of my stomach a couple of weeks ago.  I'm sure if I had the time, I would Google the answers, but at my age, I like to keep challenging myself.  So, if you see me at a traffic light and pointing with my finger, I am just pointing out the dang grill on your vehicle.