CSR - Certificate Signing Request File is when you can use a file that is designed for a digital certificate. This format is useful because it includes text that defines information about the certificate in general. You will also be able to take note about the state, email address, organization, and much more when it comes to finding out about your certificate. This just allows websites to have proof of identity. It definitely comes in handy when you need it the most, and is worth using. There is also a private key which you can use and is located within the CSR file itself.