OCSP stapling, formally known as the TLS Certificate Status Request extension, is an alternative approach to the Online Certificate Status Protocol (OCSP) for checking the revocation status of X.509 digital certificates. It allows the presenter of a certificate to bear the resource cost involved in providing OCSP responses, instead of the issuing Certificate Authority (CA).
Read more about OCSP Stapling: Motivation, Solution, Specification, Deployment, Limitations