The Free On-line Dictionary of Computing (30 December 2018):

HTTP server
web server

    (Or "web server") A server process running
   at a website which sends out web pages in response to
   HTTP requests from remote browsers.

   If one site runs more than one server they must use different
   port numbers.  Alternatively, several hostnames may be
   mapped to the same computer in which case they are known as
   "virtual servers".

   Apache and NCSA HTTPd are two popular web servers.
   There are many others including some for practically every
   platform.  Servers differ mostly in the "server-side"
   features they offer such as server-side include, and in
   their authentication and access control mechanisms.  All
   decent servers support CGI and most have some binary API
   as well.

   (1997-02-05)