“Training data” is the information AI systems study so they can learn how language, images, or patterns work. This data can include books, articles, and other publicly available information.
AI does not memorize information like a database. Instead, it learns general patterns—such as how sentences are formed or how questions are usually answered.
Because training data can vary, different AI tools may give different responses. This is another reason why AI results should always be reviewed by people before being used.