Artificial intelligence is intelligence demonstrated by machines. AI applications include advanced web search engines (e.g. Google), recommendation systems (used by YouTube, Amazon and Netflix), understanding human speech (such as Siri and Alexa), self-driving cars (e.g. Tesla), and automated decision-making. A large language model (LLM) is a type of artificial intelligence (AI) program that can recognise and generate text, among other tasks. Examples include Chat-GPT and Gemini, which are chatbot services built using LLMs. One of the most successful areas of applied AI is machine learning, based on statistical modelling techniques.