Predicting the Next Word

At its core, ChatGPT is a next-word prediction machine. Given a sequence of text, it calculates the probability of every possible next word and picks one.

The model trained on enormous amounts of text from books, articles, and websites. It does not simply store and look up texts — it extracts statistical patterns about how language works. That is why it can write about topics it never saw word for word: it learned the shape of language, not a script.