Machine learning is a subset of artificial intelligence that involves the use of algorithms and statistical models to enable a computer to learn from data, without being explicitly programmed. In other words, machine learning is a way of teaching computers to make decisions or predictions based on patterns in data, rather than relying on explicit instructions from a human programmer.

There are several different types of machine learning, including supervised learning, unsupervised learning, and reinforcement learning. In supervised learning, the computer is given a set of labeled examples and is trained to predict the correct label for new, unlabeled data. In unsupervised learning, the computer is given a set of unlabeled data and is trained to identify patterns or structure in the data. In reinforcement learning, the computer is trained to make decisions based on feedback from its environment.

Machine learning has many practical applications, including image and speech recognition, natural language processing, recommendation systems, fraud detection, and predictive maintenance.