OpenSSL is a widely used open-source software library that provides tools and protocols for implementing secure communication over computer networks. It supports encryption and decryption of data, certificate management, and the creation of cryptographic keys to ensure privacy and data integrity. OpenSSL is a foundational component for many applications, enabling the use of Secure Sockets Layer (SSL) and Transport Layer Security (TLS) protocols to protect sensitive information such as passwords, credit card numbers, and other confidential data exchanged over the internet.