Transport Layer Security (TLS) certificates are crucial for securing network communications in Couchbase Server deployments, ensuring confidentiality, integrity, and authenticity of data exchanged between clients and servers. This guide elaborates on configuring and utilizing TLS certificates within Couchbase, starting with an overview of TLS, its history, and components. TLS, which replaced the older SSL protocol, uses a mix of asymmetric and symmetric encryption for secure connections, leveraging digital certificates that bind an entity’s identity to a cryptographic key pair. Over the years, TLS has evolved through several versions, addressing vulnerabilities and improving performance, with TLS v1.3 offering enhanced security features like reduced latency and Perfect Forward Secrecy. Certificate Authorities (CAs) play a vital role in issuing and managing these certificates, ensuring trust and authenticity, while public key cryptography and digital signatures provide mechanisms for secure communication and data integrity. The guide also discusses the structure and purpose of X.509 certificates within the public key infrastructure, emphasizing the importance of the Subject Alternative Name (SAN) extension for flexibility in covering multiple domains.