Embark on a journey through the recent groundbreaking developments in face recognition (FR) systems with our second edition. Initially designed for controlled conditions, FR systems have evolved to conquer real-world challenges, adapting to low-light scenarios and extended distances. Our book delves into the transformation brought about by advancements in imaging sensors and cost-effective infrared (IR) cameras, exploring intensified near-infrared (NIR), shortwave IR (SWIR), middle-wave IR (MWIR), and long-wave IR (LWIR) imagery. This edition caters to the burgeoning interest in FR technologies, aligning with recent strides in computer vision, pattern recognition, and biometric analysis. Tailored for biometrics researchers, practitioners, and students, it addresses the critical need for FR algorithms in operational environments. Our book encompasses three comprehensive sections: (a) Face Recognition and Biometric Systems: Dive into topics such as face profile, facial attractiveness, periocular and binocular recognition, and quality training for face-based examinations. (b) Biometric System Security and Attacks: Explore adversarial attacks, domain transformers, demographic fairness, ocular pathologies, and distance-based classification of biometric images. (c) Biometric Image Synthesis and Technology Enhancements:Uncover the secrets of face image synthesis, thermal band head pose estimation, facial image analysis in forensic examination, and optimal computer monitor configurations. With 13 meticulously crafted chapters, this edition provides updated insights, experimental findings, and a roadmap for the future. Each chapter delivers a rich exploration of its specific topic, weaving together background information, literature reviews, methodologies, experiments, and concluding with challenges and future directions. Elevate your understanding of evolving face recognition technologies - the future awaits!