SSLv2, or Secure Sockets Layer version 2, is a protocol designed to secure communications over a computer network. It was developed by Netscape in the early 1990s to provide encryption and authentication for data transmitted between a client and a server. However, SSLv2 has significant security vulnerabilities and is considered outdated. It has been largely replaced by more secure protocols like TLS (Transport Layer Security). As a result, most modern web browsers and servers no longer support SSLv2, emphasizing the importance of using updated security measures to protect sensitive information online.