Machine learning is revolutionary because it gives computers the ability to solve problems without being explicitly programmed. In a conventional computer algorithm, a programmer will specify the rules that explicitly determine what their software will do.
ML algorithms work differently. At a high level, they make decisions/predictions by ingesting large quantities of historical data and using that knowledge to guide their results. Some examples of ML currently being used in businesses include:
Email filters marking messages as either spam or not spam
Netflix recommending what movies/shows you are likely to enjoy
Google maps predicting how difficult parking will be at your destination
Facebook’s facial recognition identifying people in photos
Anomaly detection algorithms that can identify fraudulent purchases