A Certificate Signing Request (CSR) is required if you would like to obtain an SSL certificate which will encode all of the payment and login information which will be exchanged between your website and its users. The CSR contains info about the site plus its owner in Base64-encoded form - website address, physical address along with email, company name and unit, and the like. Based on this code, a registered SSL vendor gives you the certificate, that is digitally signed with the vendor's private key so as to identify 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 of the 4 codes - both the keys, the certificate along with the CSR. After that, you'll be able to use a URL beginning with https:// for your website instead of http:// and the site visitors will be able to view the info that you've provided for the CSR using their web browsers.