How do sub-domain names work?
Actually I want to develop platform for CVs and I bought a domain www.cv.com. Now I want the url for each user with his/her name like www.john.cv.com or www.cv.john.com.
Does single domain work for this case or do I have to buy the sub-domains too? How is it managed programmatically?
www.john.cv.com will work. Will you have to buy or not depends on your domain name provider and packages. In maximum cases atmost 5 sub domain is free if you need further you have to pay certain price.