What is Underfitting?

Underfitting is when something learns too little and can't do its job well because it didn’t pay enough attention to the details.

Imagine you're trying to draw a dog, but all you see is a ball. You think the dog looks like a ball, so you draw a perfect circle. But if someone shows you a real dog, you might be confused, it’s not a ball! That's underfitting: your drawing didn’t learn enough about what a dog actually looks like.

Sometimes, when we try to solve a problem, we don't use enough clues or examples. Like if you only saw one kind of dog before, maybe a poodle, and thought all dogs look the same. Then you'd draw a poodle every time, even if it's actually a bulldog.

It’s like trying to solve a puzzle with just two pieces when there are twenty. You might think you've got it figured out, but you're missing most of the picture. Your answer is simple, but not quite right, it doesn’t match what you’re supposed to learn.