This review paper provides a comprehensive overview of cryptography and its role in JSON Web Tokens (JWT), focusing on secure information exchange in modern web applications and microservices architectures. It introduces key cryptographic concepts, including symmetric and asymmetric encryption, hashing, and digital signatures. It then explores the structure and functionality of JWT and its use in authentication and authorization. The paper also explores JSON Web Signature (JWS) and JSON Web Encryption (JWE), detailing their processes for digital signing, verification, and secure data encryption. Emphasizing the importance of strong encryption, proper key management, and secure transport protocols, the review underscores the need for continuous updates to cryptographic practices to maintain the integrity, confidentiality, and authenticity of information in modern systems, and understanding these concepts becomes increasingly critical for developers, system architects, and security professionals alike.