{{lowercase}} thumb|221x144px|right|PC clients communicating via network with an '''HTTPd''' process serving static content only '''HTTPd''' is a software program that usually runs in the background (i.e. a so-called "daemon"), as a process, and plays the role of a server in a client–server model using the HTTP and/or HTTPS network protocol(s).

The process waits for the incoming client requests and for each request it answers by replying with requested information, including the sending of the requested web resource, or with an HTTP error message.

'''HTTPd''' stands for ''Hypertext Transfer Protocol daemon''.

It usually is the main software part of an '''HTTP server''' better known as a '''web server'''.<ref name="http-server-httpd">{{Cite web|url=https://httpd.apache.org/docs/2.4/programs/|title=Server and supporting programs|author=|publisher=Apache: HTTPd server project|year=2021|access-date=2021-11-19|language=en}}</ref>

Some implementations are: * Apache HTTP Server * BusyBox httpd * Lighttpd HTTP server * Nginx HTTP and reverse proxy server * OpenBSD's httpd (<small>since OpenBSD 5.6</small>) * NCSA HTTPd * Internet Information Services

==See also== * Web server * Comparison of web server software

==References== {{Reflist}}

==External links== * [https://httpd.apache.org/docs/2.4/programs/httpd.html Example of an HTTPd: httpd - Apache Hypertext Transfer Protocol Server]

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