"Deep learning" refers to a subset of machine learning that employs neural networks with many layers to analyze and interpret complex data patterns. Unlike traditional algorithms, deep learning models can autonomously learn from vast amounts of unstructured data, such as images, audio, and text. This ability allows for significant improvements in tasks like image recognition, language translation, and autonomous driving. The advancements in computational power and availability of large datasets have fueled deep learning's growth, making it a cornerstone of modern artificial intelligence applications.