Applied on: Windows and Linux (both) hosting
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.
The wild card DNS record in DNS of a domain represent the primary domain and used to redirects requests for non-existent domain names towards primary domain. For example if you have a wild card DNS record of your domain and type xyz.domain.com (here "xyz" sub-domain not exist) it will redirects the request to mydomain.com. In Wildcard DNS records there is a single "*" (asterisk) at the leftmost DNS label, like *.arvixe.com. Using of asterisks at other location in the domain name will not work. neither *xyz.arvixe.com nor xyz.*.arvixe.com work as wildcard DNS records.
The wild card DNS record is specified by using a * sign as the leftmost part of a domain name, e.g. *.mydomain.com. When adding wild card DNS, the "A" record type needs to create with "*" as data for the domain's dedicated IP address This wild card DNS feature requires enabling at server. If you have dedicated IP configured for your other sub-domain, you can also use that IP so not exist sub-domain will redirect to website of that particular sub-domain.