A CSR file is a file created as a signing request for a digital certificate. It contains an encrypted block of text that identifies the applicant of the certificate and includes encrypted data for country, state, organization, domain, email address, and public key. The file is used by a Certificate Authority to establish proof of identity for Web sites.
CSR files are generated using a public and private key. The public key is included in the CSR file, and the private key is used to digitally sign the CSR file.