Why there're two servers in http HEAD request?

[papakota]

Hello!

I use Ubuntu Desktop's terminal where I type the following command:

HEAD [sitename.com...] HTTP/1.1

In the reply I see one server, say, for Google it could be gws or most of the time it's nginx and then below that, there's Apache. How come there're 2 of them for one site?

 

[imagoon]

nginx is likely configured as a caching front end for the Apache server.

 

[papakota]

Thanks for your reply!