PEM is a widely used encoding format for security certificates. Syntax and content is defined by X.509 v3 standards for digital certificates, defined in IETF RFC 5280 specifications. The main file extensions are .pem, .crt, .ca-bundle.
A PEM certificate is a base64 (ASCII) encoded block of data encapsulated between
-----BEGIN CERTIFICATE -----
-----END CERTIFICATE ----- lines.
Both PEM format of the certificate is available for download in your Namecheap account after the certificate has been issued, as well as it is emailed to the administrative contact address for the SSL order.