A Certificate Signing Request (CSR) is required when you wish to have an SSL certificate which will encode all the payment and login info which will be exchanged between your website and its visitors. The CSR contains info about the site and its owner in Base64-encoded form - website address, physical address plus email, company name and unit, etc. Based upon this code, an authorized SSL vendor issues the certificate, which is digitally signed with the vendor's private key to recognize that they're a dependable issuer. Throughout the CSR generation, a unique private key is also generated and the installation of the SSL involves all 4 codes - the two keys, the certificate along with the CSR. After that, you can use a URL beginning with https:// for your website instead of http:// and your website visitors will be able to view the information that you have provided for the CSR using their web browsers.