A Certificate Signing Request (CSR) is a file you use to request an SSL certificate from a Certificate Authority (CA). The CSR contains information that will be included in your certificate such as your name, address, domain name, and email, along with your public key. The Certificate Authority will then validate the information in the CSR to ensure it's correct before creating your SSL certificate.
The CSR must be created on the server where the SSL certificate will be used. There are two ways to create a CSR at DreamHost. View the articles below for further information: