Clustering, a key technique in unsupervised learning, was first introduced by H.E. Driver and A.L. Kroeber in 1932 and has since evolved into a crucial tool for discovering patterns in unlabeled datasets across various fields such as healthcare. It involves grouping data points into clusters based on their similarities, with the aim of capturing meaningful structures within the data. A prominent clustering algorithm is K-means, which partitions data into K clusters by iteratively assigning data points to the nearest centroid and recalculating centroids until optimal solutions are found. Despite its simplicity and efficiency, K-means can struggle with non-spherical clusters and requires predefined cluster numbers, which can be estimated using methods like the Elbow or Silhouette method. Alternatives such as Gaussian Mixture Models (GMM) offer more flexibility by using probability distributions to model data, though K-means remains popular due to its speed and ease of use. Applications of K-means include customer segmentation, fraud detection, document classification, geospatial analytics, and image segmentation. While K-means is advantageous for its scalability and low computational cost, its effectiveness can be limited by the choice of initial values and the curse of dimensionality.