What best describes unsupervised learning?

Unsupervised learning is best described as a method where patterns are found in data without labels. This approach focuses on discovering inherent structures and relationships within the dataset without the guidance of predetermined outcomes. In unsupervised learning, algorithms analyze the data to identify clusters, groupings, or associations, allowing for insights that may not be unveiled through supervised methods, which rely on labeled data.

For example, in a dataset containing various customer behaviors, unsupervised learning can uncover different segments of customers based on their purchasing patterns, providing valuable information for marketing strategies. This process of exploration and pattern recognition is fundamental in fields such as clustering and anomaly detection. In contrast, the other options describe learning strategies that depend on either specified outputs or trial-and-error methods, which do not align with the characteristics of unsupervised learning.