Web server

A web server can, in general, contain one or more websites.

A website or web site is a collection of related network web resources, such as web pages, multimedia content, which are typically identified with a common domain name, and published on at least one web server.

A web server is server software, or hardware dedicated to running such software, that can satisfy World Wide Web client requests.

Websites are stored in computers that are running a program called a web server that responds to requests made over the Internet from web browsers running on a user's computer.

Pages delivered are most frequently HTML documents, which may include images, style sheets and scripts in addition to the text content.

Web browsers receive HTML documents from a web server or from local storage and render the documents into multimedia web pages.

The primary function of a web server is to store, process and deliver web pages to clients.

For example, web browsers are clients that connect to web servers and retrieve web pages for display.

A user agent, commonly a web browser or web crawler, initiates communication by making a request for a specific resource using HTTP and the server responds with the content of that resource or an error message if unable to do so.

When a user requests a particular website, the web browser retrieves the necessary content from a web server and then displays the resulting web page on the user's device.

The primary function of a web server is to store, process and deliver web pages to clients.

On a network, a web browser can retrieve a web page from a remote web server.

This usually means that no additional software has to be installed on the client computer since only a web browser is required (which now is included with most operating systems).

Operating systems are found on many devices that contain a computer – from cellular phones and video game consoles to web servers and supercomputers.

Usually, this function is used to generate HTML documents dynamically ("on-the-fly") as opposed to returning static documents.

Consequently, a static web page displays the same information for all users, from all contexts, subject to modern capabilities of a web server to negotiate content-type or language of the document where such versions are available and the server is configured to do so.

CERN httpd (later also known as W3C httpd) is an early, now discontinued, web server (HTTP) daemon originally developed at CERN from 1990 onwards by Tim Berners-Lee, Ari Luotonen and Henrik Frystyk Nielsen.

Pages delivered are most frequently HTML documents, which may include images, style sheets and scripts in addition to the text content.

The Web server is another common host environment.

On an Apache server, this is commonly /home/www (on Unix machines, usually /var/www).

The Apache HTTP Server, colloquially called Apache, is free and open-source cross-platform web server software, released under the terms of Apache License 2.0.

A user agent, commonly a web browser or web crawler, initiates communication by making a request for a specific resource using HTTP and the server responds with the content of that resource or an error message if unable to do so.

Web site administrators typically examine their Web servers' log and use the user agent field to determine which crawlers have visited the web server and how often.

Criminal perpetrators of DoS attacks often target sites or services hosted on high-profile web servers such as banks or credit card payment gateways.

Many generic web servers also support server-side scripting using Active Server Pages (ASP), PHP (Hypertext Preprocessor), or other scripting languages.

Web development can be considered a use of glue languages, interfacing between a database and web server.

The client's user agent will translate it into a connection to with the following HTTP/2 request:

Efforts by servers hosting websites to counteract bots vary.

The former is primarily used for retrieving or modifying information from databases.

This evolved into a multitier architecture incorporating application servers and web servers with the end user interface via a web browser with the database only directly connected to the adjacent tier.

A user agent, commonly a web browser or web crawler, initiates communication by making a request for a specific resource using HTTP and the server responds with the content of that resource or an error message if unable to do so. A web server processes incoming network requests over HTTP and several other related protocols.

A stateless protocol does not require the HTTP server to retain information or status about each user for the duration of multiple requests.

Many generic web servers also support server-side scripting using Active Server Pages (ASP), PHP (Hypertext Preprocessor), or other scripting languages.

PHP is a general-purpose scripting language that is especially suited to server-side web development, in which case PHP generally runs on a web server.

By Christmas 1990, Berners-Lee had built all the tools necessary for a working Web: the HyperText Transfer Protocol (HTTP) 0.9, the HyperText Markup Language (HTML), the first Web browser (which was also a HTML editor and could access Usenet newsgroups and FTP files), the first HTTP server software (later known as CERN httpd), the first web server, and the first Web pages that described the project itself.

This feature is used for submitting web forms, including uploading of files.

CGIs may be written in other languages than Perl (compatibility with multiple languages is a design goal of the CGI protocol) and there are other ways to make Perl scripts interoperate with a web server than using CGI (such as FastCGI, Plack or Apache's mod_perl).

Internet Information Services (IIS, formerly Internet Information Server) is an extensible web server created by Microsoft for use with the Windows NT family.

Usually, this function is used to generate HTML documents dynamically ("on-the-fly") as opposed to returning static documents.

A program running on a web server (server-side scripting) is used to generate the web content on various web pages, manage user sessions, and control workflow.

LiteSpeed Web Server (LSWS), is a proprietary web server software for which an open source variant is also available.