In plain English
AI models can produce convincing answers even when their information is incomplete or incorrect. Grounding gives them additional information to work from, such as company documents, search results, or trusted databases. This helps the model base its response on relevant evidence rather than relying entirely on what it learned during training. Grounding can reduce hallucinations, but it does not guarantee a correct answer.
Example
An AI customer service assistant consults a company's latest return policy before telling a customer whether an item qualifies for a refund.