Machine learning enables facial recognition systems by utilizing algorithms that can learn and identify patterns in images. These systems are trained on large datasets containing numerous facial images, allowing them to distinguish features such as the shape of the eyes, nose, and mouth. Once trained, the machine learning model can analyze new images and match them against the known database to identify individuals. This technology is widely used in security, social media tagging, and smartphone authentication, enhancing ease of access while maintaining a level of security in various applications.