An HTTP server is a computer (

software Software is a set of computer programs and associated software documentation, documentation and data (computing), data. This is in contrast to Computer hardware, hardware, from which the system is built and which actually performs the work. ...

) program (or even a

software component Component-based software engineering (CBSE), also called component-based development (CBD), is a branch of software engineering that emphasizes the separation of concerns with respect to the wide-ranging functionality available throughout a give ...

included in an other program) that plays the role of a server in a

client–server model The client–server model is a distributed application structure that partitions tasks or workloads between the providers of a resource or service, called servers, and service requesters, called clients. Often clients and servers communicate ov ...

by implementing the ''server part'' of the

HTTP The Hypertext Transfer Protocol (HTTP) is an application layer protocol in the Internet protocol suite model for distributed, collaborative, hypermedia information systems. HTTP is the foundation of data communication for the World Wide Web, ...

and/or

HTTPS Hypertext Transfer Protocol Secure (HTTPS) is an extension of the Hypertext Transfer Protocol (HTTP). It is used for secure communication over a computer network, and is widely used on the Internet. In HTTPS, the communication protocol is e ...

network protocol A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity. The protocol defines the rules, syntax, semantics and synchroni ...

(s). An HTTP server waits for the incoming client requests (sent by

user agent In computing, a user agent is any software, acting on behalf of a user, which "retrieves, renders and facilitates end-user interaction with Web content". A user agent is therefore a special kind of software agent. Some prominent examples of u ...

s like browsers,

web crawler A Web crawler, sometimes called a spider or spiderbot and often shortened to crawler, is an Internet bot that systematically browses the World Wide Web and that is typically operated by search engines for the purpose of Web indexing (''web spi ...

s, etc.) 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. An HTTP server may also have bindings to manage protocol extensions to HTTP (i.e.

WebDAV WebDAV (Web Distributed Authoring and Versioning) is a set of extensions to the Hypertext Transfer Protocol (HTTP), which allows user agents to collaboratively author contents ''directly'' in an HTTP web server by providing facilities for concu ...

, etc.) or messages of other protocols enveloped into HTTP messages (i.e.

SOAP Soap is a salt of a fatty acid used in a variety of cleansing and lubricating products. In a domestic setting, soaps are surfactants usually used for washing, bathing, and other types of housekeeping. In industrial settings, soaps are used ...

, etc.) in order to allow program-to-program communications. Implementations of an HTTP server may vary in complexity, from a manageable tiny component to a full featured program implementation of HTTP and other protocols, which maybe can run in background, as one or more

process A process is a series or set of activities that interact to produce a result; it may occur once-only or be recurrent or periodic. Things called a process include: Business and management *Business process, activities that produce a specific se ...

es, etc. An HTTP server can be found in any kind of computer, including

embedded system An embedded system is a computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is ''embedded'' ...

s and

super computer A supercomputer is a computer with a high level of performance as compared to a general-purpose computer. The performance of a supercomputer is commonly measured in floating-point operations per second (FLOPS) instead of million instructions p ...

s, also because it is a required component to run web interfaces (

web application A web application (or web app) is application software that is accessed using a web browser. Web applications are delivered on the World Wide Web to users with an active network connection. History In earlier computing models like client-serve ...

s), etc. The difference between the term

web server A web server is computer software and underlying hardware that accepts requests via HTTP (the network protocol created to distribute web content) or its secure variant HTTPS. A user agent, commonly a web browser or web crawler, initi ...

and the term HTTP server is very subtle because the two terms are almost synonyms. The first term (web server) somehow predates the second one and it refers to the purpose of serving

web content Web content is the text, visual or audio content that is made available online and user encountered as part of the online usage and experience on websites. It may include text, images, sounds and audio, online videos, among other items placed ...

in the context of a

World Wide Web The World Wide Web (WWW), commonly known as the Web, is an information system enabling documents and other web resources to be accessed over the Internet. Documents and downloadable media are made available to the network through web se ...

environment which is oriented to the interaction with human beings. That term may refer not only to the HTTP server software component but also to the whole system ( hardware and software) required to run a

website A website (also written as a web site) is a collection of web pages and related content that is identified by a common domain name and published on at least one web server. Examples of notable websites are Google, Facebook, Amazon, and Wikip ...

. The second term (HTTP server) has a technical origin bound to the software implementation of the server part of the protocol and so that term is used more to refer to it as a software component which can be used for many other purposes besides hosting public

s in

Internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a ''internetworking, network of networks'' that consists ...

or even private ''websites'' in Intranets or

Extranet An extranet is a controlled private network that allows access to partners, vendors and suppliers or an authorized set of customers – normally to a subset of the information accessible from an organization's intranet. An extranet is similar to ...

References

{{Reflist

External links

Example: Apache, HTTP server project
Servers (computing) Web server software

See also

References

External links