SSL was the cryptographic protocol that Transport Layer Security replaced as its successor.
Transport Layer Security, or TLS, developed from the Secure Sockets Layer protocol originally created for securing network communications. TLS 1.0 was published in 1999 and was based on SSL 3.0, but the name changed partly because the protocol was standardized through the Internet Engineering Task Force rather than Netscape.
TLS provides encryption, integrity protection, and authentication for connections such as HTTPS. Modern deployments use TLS versions such as TLS 1.2 and TLS 1.3, while the older SSL protocols are considered insecure and have been deprecated.
SSL is often used informally to describe modern HTTPS certificates, but current secure web connections normally use TLS. SSH and IPsec are separate security protocols serving different networking purposes.