A classifier is an algorithm or model that assigns labels or classes to observations. Classifiers are used in tasks such as spam detection, image recognition, risk scoring, and routing decisions.
A casual term for a classification model.
is an algorithm that makes predictions about the world by assigning labels to observations. Very often, predictions made by classifiers are then turned into actions, and so they affect the world. For example, a smart light classifier decides whether to turn the light on or off. This AI will automate a task that is usually done by a human, and we will say that this AI works well if it is able to guess whether a human would have turned the light on or off.