AI fundamentals

AI is software that recognizes patterns and learns from data to produce useful outputs, with large language models (LLMs, systems trained on large amounts of text to generate and transform language) being a common type you interact with through tools like ChatGPT. Models go through two training stages: pre-training, where they learn general patterns from massive text datasets, and post-training, where they're refined to follow instructions reliably, communicate clearly, and handle sensitive topics carefully through safety checks. Different models are optimized for different tradeoffs, such as reasoning models designed for complex problem-solving versus non-reasoning models built for fast, straightforward tasks.