The broad field of computer science where systems learn patterns from data rather than following explicit rules. Instead of programming a computer to recognize a cat by listing features (four legs, pointy ears, whiskers), you show it thousands of cat photos and let it figure out the pattern itself. Machine learning encompasses everything from simple linear regression to the deep neural networks powering today's AI — supervised learning (labeled examples), unsupervised learning (finding structure), and reinforcement learning (trial and error).
Why it matters
Machine learning is the foundation under everything we call "AI" today. Every LLM, every image generator, every recommendation algorithm, every spam filter — it's all machine learning. Understanding ML as the broader discipline helps you see where deep learning fits, where classical methods still win, and why "AI" is really just "ML that got really good."