Machine learning
A way of building AI in which a computer learns patterns from examples, instead of a programmer writing every rule by hand.
In traditional software, a programmer writes exact instructions: if this happens, do that. In machine learning, the programmer gives the computer many examples and a method for learning from them. The computer adjusts itself until it gets good at the task.
A spam filter is a classic example. Shown thousands of emails marked "spam" or "not spam", it learns which features tend to signal junk mail. Streaming services use similar methods to suggest films based on what people with similar tastes watched.
Machine learning is the main approach behind most AI in use today, so the two terms are often used as if they mean the same thing. The key point is that a learned system is only as good as its examples. If the training data is incomplete or unfair, the results can be too. See bias.
Related: Training data, Neural network, Algorithm