A password-protected container format (RFC 7292) that bundles a private key together with its certificate and, usually, the issuing chain. Files use the .pfx or .p12 extension and are the normal way to move an identity — key and certificate together — between systems. Because it contains the private key, a PKCS#12 file must be handled as a secret, not as a public certificate.
PKCS#12
Public-Key Cryptography Standards #12