OpenSSL is a widely-used software library that provides tools for implementing secure communication over computer networks. It supports various cryptographic functions, including encryption, decryption, and digital signatures, making it essential for securing data transmitted over the internet. Developed as an open-source project, OpenSSL is utilized by many applications and services, including web servers and email clients. It helps ensure that sensitive information, such as passwords and credit card numbers, remains confidential and protected from unauthorized access.