Certificate Signing Request (CSR)
Definition - What does Certificate Signing Request (CSR) mean?
A certificate signing request (CSR) is basically a message that an applicant, usually a person or organization who owns a website that needs to be secured, sends to a certification authority in order to apply for a specific digital identity certificate.
This is a standard procedure in a public key infrastructure (PKI) which allows website owners to prove to their users that the website they are visiting is authentic.
Techopedia explains Certificate Signing Request (CSR)
The CSR also contains the public key of the website which will be included in the certificate while a private key is produced at the same time the request is created.
Once received, the certification authority will create a SSL certificate from the CSR and it will only work with the private key which was created at the same time with the CSR used.
If the private key is lost, then the SSL certificate will no longer work.