A wildcard host or subdomain is a domain that is a part of a top-level domain under the DNS hierarchy. It is used as an easy way to create many unique web addresses for specific purposes.

For example, it could make it easier for users to remember and navigate to the demo of a product's site by placing it at the address demo.v2mysite.com. In this case, the subdomain is demo.v2mysite.com, whereas the main domain is mysite.com.

A wildcard host or subdomain is also known as a child domain. We have a parent domain, v2mysite.com, and I'm about to show you how to create a subdomain demo prefixed with the main domain, like demo.v2mysite.com. We can have different names and unlimited wildcard hosts for our parent domain. A wildcard host or subdomain website host doesn't require any separate payment or registration. The purpose of a subdomain is to have a separate URL of for products or training either for internal or external use. You can create unlimited wildcard hosts based on the primary domain, which requires registration, and you have to pay for an annual or quarterly subscription.

Here, you can see a few examples of wildcard hosts: