What does anomaly detection identify in machine learning?

Anomaly detection is a technique used in machine learning to identify rare observations that significantly differ from the majority of the data. This difference can indicate abnormal behavior or unexpected patterns, which may be critical for various applications such as fraud detection, network security, fault detection, and monitoring environmental changes.

By focusing on rare events, anomaly detection helps uncover insights that would otherwise be missed in the analysis of common trends and regular patterns. This capability to identify outliers plays a crucial role in improving system performance, ensuring security, and providing deeper insights into complex datasets. In contrast, options related to common trends, non-significant differences, or regular patterns do not align with the purpose of anomaly detection, which specifically concerns identifying those deviations from what is expected.