In the modern world, trustworthy and secure identity is essential for a number of uses, such as unlocking personal gadgets and gaining access to secure areas. Conventional techniques, such as PINs and passwords, have shown to be vulnerable to fraud and illegal access. These vulnerabilities have been addressed by the development of biometric authentication, which makes use of an individual's distinct physiological and behavioral characteristics. Unimodal biometric systems concentrate on a single feature, although they frequently face difficulties like noise and spoofing assaults. By merging characteristics from several modalities, multimodal biometric systems provide an answer and improve identification robustness and accuracy. In order to increase identification security and accuracy, this article investigates the combination of hand geometry, palm print, fingerprint, and facial biometrics. Different integration situations and modes of operation for multimodal biometric systems are examined, as well as various fusion methodologies. In summary, the paper ends with implications for biometric systems practitioners, academics, and policymakers as well as a discussion of relevant research topics.