Since the launch of ChatGPT, there has been a surge of interest in generative AI (genAI), leading tech vendors and enterprises to rapidly integrate genAI into products and business processes. This surge has introduced a new vocabulary, resulting in a language barrier that makes it difficult for tech and data leaders and their teams to communicate effectively. This report provides definitions and Forrester’s point of view on crucial genAI terms, particularly those related to large language models (LLMs).