This document reviews three categories of fingerprint recognition techniques: minutiae-based matching, pattern based matching, and correlation-based matching. Minutiae-based matching is the most popular and analyzes ridge endings and bifurcations. Pattern based matching uses fingerprint patterns like loops and whorls. Correlation-based matching overlays images and computes pixel correlations. The document also discusses challenges with fingerprint identification like low quality images and evaluates different enhancement and feature extraction methods.