Top "Server-name" questions

nginx server_name wildcard or catch-all

I have an instance of nginx running which serves several websites. The first is a status message on the server's …

nginx catch-all server-name
What's the difference between ServerVariables["HTTP_HOST"] and ServerVariables["SERVER_NAME"]?

I'm confused about the difference between these two server variables. Checking the IIS documentation, it states :- HTTP_HOST Returns …

asp.net iis http-host server-name