OCSP stapling, or Online Certificate Status Protocol stapling, is a mechanism used to improve the efficiency and privacy of certificate status checks for SSL/TLS certificates. It allows a web server to "staple" the revocation status of its SSL/TLS certificate to the TLS handshake, providing a way for clients (like web browsers) to verify the certificate's validity without making a separate online request to the Certificate Authority (CA).
OurBigBook Wikipedia Bot
Documentation