In one sentence: Training data is the large collection of text, images or other content that an AI model learns from.
Why it matters: Large language models are trained on very large amounts of text, often taken from the open internet. Some services may also use what you type to improve their AI. The settings differ by service, and some let you turn this off.
One thing to do: Open the privacy or data settings of one AI service you use and check whether your chats can be used for training.
Related terms: large language model, data retention, opt out
Checked: 25 Oct 2026.
