A web server is a server that accepts HTTP requests from clients, usually web browsers , and issues HTTP responses to them, usually with an HTML page, image, file , media stream, or other data.
A web server refers both to software that performs the functions of a web server, and directly to a computer (see: Server (hardware) ) on which this software runs.
The client , which is usually a web browser , sends requests to resources to the web server indicated by URLs . Resources are HTML pages, images, files, media streams, or other data that a customer needs. In response, the web server sends the requested data to the client. This exchange takes place over HTTP .
Additional features
Web servers may have various additional functions, for example:
- automation of web pages;
- logging of user access to resources;
- user authentication and authorization ;
- support for dynamically generated pages ;
- HTTPS support for secure client connections.
Often, a mail server is also installed on the computer along with the web server .
Software
As of August 2011, the most common web server, occupying more than 65% of the market [1] , is Apache , a free web server, most often used in UNIX-like operating systems ;
Some other famous web servers:
- IIS from Microsoft , distributed with the OS family of Windows
- nginx is a free web server developed by Igor Sysoev since 2002 and is very popular on large sites [2] , [3]
- lighttpd is a free web server.
- Google Web Server is a web server based on Apache and modified by Google .
- Resin is a free web application server.
- Cherokee is a free web server, managed only through a web interface.
- Rootage is a web server written in java.
- THTTPD is a simple, small, fast and secure web server.
- Open Server - a free program with a graphical interface uses a variety of exclusively free software.
- H2O is a free fast web server written in C.
Customers
As clients, various programs and devices can be used to access web servers:
- a web browser running on a desktop or portable device (for example, a pocket PC );
- various programs that independently access web servers to receive updates or other information (for example, the antivirus can periodically request updates from its specific web server for its databases);
- a mobile phone that accesses web server resources using WAP ;
- other digital devices or home appliances .
The difference between a web server and an application server.
See also
- Web server list
- Proxy server
Notes
- ↑ August 2011 Web Server Survey (English) . Netcraft (August 5, 2011). Circulation date August 6, 2011. Archived August 24, 2011.
- ↑ Internet 2009 in figures and facts . Habrahabr (January 24, 2010). The appeal date is June 17, 2010.
- ↑ February 2011 Web Server Survey (English) . Netcraft (February 15, 2010). Circulation date February 20, 2011. Archived August 25, 2011.
Links
- Netcraft - definition and collection of statistics used in the world of web servers.
- Web server definition service on the site “ Whois- service Russia”.