A server certificate is a certificate used to secure communication between the server and the clients.
It follows a constant process of encoding and decoding in the relay information from the server to the client or the other way around. Both the server and the client send encrypted data. It decodes data for comprehension at both ends. These SSL certificates are very small in size and comprise of an organization-specific cryptographic key. This key authenticates the user who accesses the web server and establishes a secure connection. Thereby, providing for a secure method of communication.