Deep learning is a subset of machine learning that utilizes artificial neural networks with multiple layers to learn and extract complex patterns from data. In other words, deep learning is a specific approach within the broader field of machine learning that focuses on training deep neural networks. Neural networks, on the other hand, refer to the computational models inspired by the structure and function of the human brain, which can be used in various machine learning techniques, including deep learning. In essence, deep learning is a methodology that employs neural networks with multiple layers to achieve powerful learning capabilities and solve complex problems.