Specify the host you would like to issue the SSL certificate for. Some examples are www.yourdomain.com, yourdomain.com (without the www), secure.yourdomain.com, ssl.yourdomain.com. The choice is yours, but do keep in mind that only this name will be secured by the SSL, so double-check your spelling!
What are dedicated IPs and what are their benefit?
IP addresses are a series of numbers (like 18.104.22.168) used to identify resources on the Internet. When a website is assigned a Dedicated IP instead of a Shared IP, it becomes the only website that uses that IP address.
WHC recommends Dedicated IPs for a better SSL support, performance and access for your important sites. Without dedicated IPs, sites use shared IPs and must rely on a technology called SNI to function. Since SNI technology is not available on some older browsers, your site may be inaccessible for up to 3% of all your users. WHC recommends you add a dedicated IP for each important website (more than 10,000 visitors per month) on your server.
By default, servers are delivered with a single IP address that is shared across all websites that you host on that server. WHC recommends 5 IP addresses for most common configurations, which will include: 2 dedicated IPs for your nameservers, 1 dedicated IP for the server itself, 1 dedicated IP for your main website, and 1 shared IP for all your other websites.