What is the difference between Artificial Intelligence, Machine Learning, and Deep Learning?

Artificial Intelligence (AI) is the broadest concept — any technique that enables machines to mimic human intelligence. Machine Learning is a subset of AI where systems learn from data rather than following explicit rules. Deep Learning is a subset of ML that uses multi-layered neural networks (deep neural networks) to learn hierarchical representations. Think of it as nested circles: AI ⊃ ML ⊃ Deep Learning. Deep Learning requires more data and compute but achieves state-of-the-art results on tasks like image recognition and NLP.