How Do Machines Learn?

Now that we have such amazing data sets, algorithmic learning is far more effective. CGP Grey also put out a video that describes what's going on inside the algorithm. He uses metaphors, such as a teacher bots and builder bots, to try and explain the machines' process of learning. "In ye olden days, humans built algorithmic bots by giving them instructions the humans could explain: if this, then that," he says. "But many problems are just too big and hard for a human to write simple instructions for." Image recognition is the classic example of a "just too big and hard" problem. How do I explain the concept of a "bee" to a computer so that it can correctly identify one in any given photo?