Provides a broad definition of unsupervised machine learning followed by a description of what foundational large language models are, how they are trained and how they are used. Focuses on ChatGPT as an example of a practical user interface with LLM’s. Teaches, with examples, a step-by-step prompting method to maximize useful GPT outputs. Closes with descriptions of drawbacks and risks of generative AI text based tools to allow practitioners to make informed decisions on their use.