Explain · Like I'm five version
Machine learning in terms of training a puppy
Is teaching a computer to think just like teaching a puppy to sit and stay?
When you teach a computer to learn, you are really just giving it a giant pile of examples to look at. It is exactly like training a puppy to go to the toilet outside instead of on your favourite rug. You show the puppy a spot in the garden and say good dog when it gets it right. With a computer, you show it thousands of pictures of cats until it learns to spot the pointy ears and whiskers all by itself.
The computer does not actually know what a cat is, just like a puppy does not know why you want it to sit. It just wants the reward of a correct answer. If the puppy sits, it gets a tasty treat or a pat on the head. If the computer gets the right answer, the clever maths inside tells it to keep doing that exact same thing next time. It is all about repeating the same lesson until the mistakes go away.
Sometimes the puppy gets confused and chews your slippers instead of its toy. The computer can be just as silly if you give it the wrong kind of pictures. If you only show it photos of dogs in hats, it will think every dog in the world is wearing a fancy party accessory. It is very hard work to make sure your computer learns the right rules, just like making sure your puppy does not jump on the nice postman.
Where the analogy breaks downA puppy eventually understands affection and companionship, whereas a computer simply processes numbers without any feelings or loyalty at all.