What is the use of * in Hostname

Question

Why we create Site like below in Site definition:

  <site name="Test Site">
        <patch:attribute name="hostName">*</patch:attribute>
        <patch:attribute name="targetHostName">*</patch:attribute>
      </site>

Answer 1

When a user visits site using a host name (ex.xyz.com), sitecore code will go into site definitions, from top to bottom and try to find any matching First site definition for that. but hostName is not a required attribute. Default "website" doesn't have one either. The host name of the incoming url. May include wildcards *(ex. http://www.site.net, *.site.net, .net, pda., print..net) It’s possible to set more than one mask by using ‘|’ symbol as a separator (ex. pda.|print..net).

So * in your hostname doesn't have any meaning or you can say allowing all type of URLs. Sitecore has defined "website" site definition in a way, that all the non-matching url request are matched into "website" site definition. i.e. by not having "hostName" attribute and virtualPath/physicalPath are set to "/".