What are pre-trained models?

A pre-trained model is like a super-smart robot that already knows how to do many things before you even start using it.

Imagine you have a friend who has read every book in the world. You ask them a question about a story, and they know exactly what happens next, no matter how strange or complicated it is. That’s kind of like a pre-trained model. It's been trained on lots of data, maybe millions of sentences, so it already understands language really well.

Think of it as learning to read by practicing with many, many books. A pre-trained model has done this practice already. When you use it, you're like the friend who just needs a little help finishing a story or solving a puzzle, the robot has already learned most of the rules.

If your robot had to learn everything from scratch every time you asked them a question, that would take a really long time. But since they've already practiced with so many stories and sentences, they can answer questions much faster, just like how you don’t need to read every book in the world to guess what happens next in a story.