Remember that the DNS is a protocol (known as the TCP/IP protocol suite) refers to exchange of data over Internet among computers, and on many private networks.  It has set of standards. Basically DNS protocol converts a user-friendly domain name (like arvixe.com) into an Internet Protocol (IP) address like 108.175.146.148 so the computers can identify each other over network. Normally in share hosting environment, a single IP address use to serve various domains. In many cases you might need to have sub domains like support.domain.com. While it serve domain owners on various way, user also can directly go to this domain’s website instead of using a link at main domain.com. What about if someone type a sub-domain that is not present at your domain for example suport.domain.com (mistakenly type suport instead of support). The wild card DNS helps to catch this sort of mistakes.