PFX File from CER/PEM(Public) and Key File(Private)

https://support.globalsign.com/ssl/ssl-certificates-installation/install-pfxpkcs12-internet-information-services-iis-7

openssl pkcs12 -export -in linux_cert.pem -inkey privateky.key -out output.pfx

PFX file has a Password - This password is for protecting contents of this container to be visible to others except those who know password

Private Key - While Making a Private Key -We too give a Passphrase for encryption

PrivateKey Passphrase and PFX Container Passphrase are different.

https://stackoverflow.com/a/808742/2413870