Generative AI & Large Language Models

Definition: Generative AI creates new content — text, images, audio, code — rather than just analysing existing data. The tools behind text generation are Large Language Models (LLMs).

What is an LLM?

A Large Language Model like the one behind ChatGPT is trained on enormous amounts of text. At its core it does one thing astonishingly well: predict the next word, over and over, to produce fluent, relevant responses. From that simple idea comes the ability to write, summarise, translate, and answer questions.

What generative AI can create

• Text — articles, emails, code, summaries (ChatGPT, Claude, Gemini)
• Images — art and photos from a description (Midjourney, DALL-E)
• Audio & video — voices, music, and clips

The catch

Because it predicts likely words rather than looking up facts, generative AI can sound confident and still be wrong. Always verify anything important.

💡 Tip: the skill of writing good instructions for these tools is called prompt engineering — we have a full free course on it.