Or "smahts" if you're from my neck of the woods.
Intelligence is so closely linked to how we value ourselves, that it's difficult to remember there's different ways of learning and doing and exploring the world.
Book Smarts Means Learning For Learning's Sake
Book smarts are a commodity. We pay hundreds of thousands of dollars for a college degree so we can debate the problematic nature of policies, literature, or culture. We sign up for classes. We apply to prestigious universities and live every minute of high school just to get in. We scramble to move to towns with good schools to give our kids the chance to learn.
Book smarts are easy to come by. If you're dedicated enough to learning, picking up a book will do. As "geekiness" becomes more and more mainstream (see the successes of Marvel movies and more) it's now more acceptable to let your enthusiasm for obscure works of Roman philosophers or English Romantic poets or the entire works of Joss Whedon fly.
Street Smarts Means Learning By Doing
Street smarts come from experience. It takes years of the "real world" to know what works and what doesn't, how to talk to people, not books, and how to take what you learned in a book and apply it to your life.
It's a trial by fire. You either succeed, or you fail. And usually, with street smarts, the stakes are high. For college graduates, that's not so easy. You've just spent four years talking about issues, dissecting them in labs, leading round table discussions. You can be an African Studies major and never travel to the continent of Africa. All you have is your book smarts.
Book smarts might give you great cocktail conversations; street smarts are the cocktails. When we leap to fly and fall, we fail. That's street smarts. That's knowing what to do at 3AM when your flight is canceled and you don't speak the language and you have to get home. It's the gut intuition you have when you hear an idea that means something. It's what you feel when you score a goal, or finish a marathon.
One isn't better than the other. But we can't rely just on our book smarts to get us somewhere in life. You have to go out there and do something.