A Secure Sockets Layer (SSL) certificate is a digital certificate employed to establish secure communication between two systems, such as a web server and a web browser. SSL certificates utilize public-key cryptography to guarantee the security and encryption of data transmitted between these systems. The certificate includes the name of the certificate holder, the public key of the certificate holder, the identity of the issuing Certificate Authority (CA), the validity period of the certificate, and the digital signature of the issuing CA. SSL certificates are commonly utilized to secure web traffic, particularly e-commerce transactions, and are also employed for encrypted communication between email clients and servers. Additionally, SSL certificates are utilized for secure access to corporate networks, ensuring that only authorized users can gain entry. These certificates are issued by a Certificate Authority, which verifies the identity of the certificate holder and validates the authenticity of the certificate.

In addition to securing typical web traffic, SSL certificates are utilized to secure a range of other services, including cloud storage, file sharing, and virtual private networks (VPNs). Furthermore, SSL certificates can be employed to authenticate the identity of a user, guaranteeing that only verified users can access an application or service. Moreover, SSL certificates can be used in conjunction with two-factor authentication, such as a password and a one-time token from a mobile device, to provide an additional layer of security.