A web server is a computer program and server that allows for hosting of websites and web applications. It accepts requests from browsers and returns HTML documents and other content. Common technologies used on web servers include CGI scripts, SSL security, and ASP to provide dynamic content and server-side processing. Web servers work by accepting connections from browsers, retrieving content from disk, running local programs, and transmitting data back to clients as quickly as possible while supporting threads and processes.

1. Web Server A software program or server computer equipped to offer World Wide Web access. Web servers allow you to serve content over the Internet using the Hyper Text Markup Language (HTML). The Web server accepts requests from browsers like Netscape and Internet Explorer and then returns the appropriate HTML documents.

2. Web Server A web server is a computer with special software to host web pages and web applications. A computer that provides Web services and pages to intranet and Internet users. A web server serves web pages to clients across the Internet or an Intranet. The web server hosts the pages, scripts, programs, and multimedia files and serves them using HTTP, a protocol designed to send files to web browsers and other protocols.

3. Web Server Cont... A number of server-side technologies can be used to increase the power of the server beyond its ability to deliver standard HTML pages These include CGI scripts, server-side includes, SSL security, and Active Server Pages(ASPs)

4. How Web servers Work - Overview

5. How Web servers Work - Overview Cont... Perhaps the most important expansion on this was the concept of dynamic content (i.e., Web pages created in response to a user's input, whether directly or indirectly). The oldest and most used standard for doing this is Common Gateway Interface (CGI) It basically defines how a Web server should run programs locally and transmit their output through the Web server to the user's Web browser that is requesting the dynamic content.

6. How Web servers Work - Overview Cont...

7. Web Server and Browser Interaction A Web Browser acts as an interface between the user and the Web server The browser carries out the following on behalf of the user Contacts a web server Sends a request for information Receives the information and Displays it on the user's computer

8. How Does a Web Server Accept Connections? Accept network connections from browsers Retrieve content from disk Run local CGI programs Transmit data back to clients Be as fast as possible Support multi-threading and multi-processing

9. How Do You Organize Web Servers for Performance? Dynamic content typically relies on heavy database usage or processing of other program code, which takes up many server-side resources. Web site that has grown popular beyond its immediate means of serving content and ways to spread this load out

10. Load Balancing DNS balancing (round-robin type) Hardware load balancing Software load balancing Reverse proxying Content spreading across hosts Content spreading across outsourced providers

11. Load Balancing Cont...

12. How Does Web Server Security Work? Security of the data stream itself so that it may not be viewed or modified by a malicious third party Security of the content itself -- the authentication and authorization of people to view and change that content

14. Server Version Operating System Price Range AOLserver 3.1 Digital UNIX, SCO, HPUX, Windows NT, Linux, Windows 95, FreeBSD, Windows 98, IRIX, Solaris Free Allegro RomPager 3.6 NetBSD, Digital UNIX, BSDI, AIX, OS/2, Windows 3.x, SCO, HPUX, Novell NetWare, Macintosh, Be OS, Embedded, Windows NT, Linux, Windows CE, MS-DOS, VM/CMS, MVS,VMS, QNX, S/400, Windows 95, FreeBSD, Windows 98, IRIX, Solaris, Amiga Contact Sales@ allegrosoft .com AnalogX SimpleServer :WWW 1.05 Windows NT, Windows 95, Windows 98 Free Apache 1.3.17 NetBSD, Digital UNIX, AIX, OS/2, Windows 3.x, SCO, HPUX, Novell NetWare, Macintosh, Be OS, Windows NT, Linux, VMS, AS/400, Windows 95, FreeBSD, IRIX, Solaris Free Baikonur Web App Server 1.9 Windows NT, Windows 95 $995 Commerce Server/400 1.0D AS/400 $4995 (suggested retail) EMWAC HTTP Server 0.991 Windows NT Free EmWeb Embedded Web Server R5_2_1 HPUX, Embedded, Windows NT, Linux, Windows 95, Windows 98, Solaris Call Agranat Systems Enterprise Server 3.0 Novell NetWare $1,295 GoAhead WebServer 2.1 HPUX, Embedded, Windows NT, Linux, Windows CE, QNX, Windows 95, Windows 98, IRIX Free, embedded web Server Internet Information Server 4.0 Windows NT Free with NT 4.0 option pack Java Server 1.1 OS/2, HPUX, Windows NT, Linux, Windows 95, IRIX, Solaris $295

15. Server Version Operating System Price Range Lotus Domino Go Webserver 4.6.1 Digital UNIX, AIX, OS/2, HPUX, Windows NT, Windows 95, IRIX, Solaris $495; free demo Netscape Enterprise Server 3.5.1 Digital UNIX, AIX, HPUX, Windows NT, IRIX $1,295 Oracle Web Application Server 3.01 HPUX, Windows NT, Windows 95, Solaris call Oracle Spinnaker 3.0 Windows NT, Windows 95 $249 Viking 1.06 Windows NT, Windows 95, Windows 98 $100 for 90-day trial WebBase 4.5 Windows 3.x, Windows 95 $695 WebSite Professional 2.5.8 Windows NT, Windows 95, Windows 98 $799 Xitami 2.4d8 NetBSD, Digital UNIX, BSDI, AIX, OS/2, Windows 3.x, SCO, HPUX, Windows NT, Linux, VMS, QNX, Windows 95, FreeBSD, IRIX, Solaris Xitami: free: Xitami/Pro: $99

17. Personal Web Server Microsoft's Personal Web Server (PWS) is a scaled-down version of the commercial Information Internet Server (IIS) included with the Server edition of Microsoft Windows NT. Designed for Windows 95/98/ME and Windows NT Workstation users. PWS is a great entry-level Web server that makes it easy to publish personal home pages, serve small Web sites, and share documents via a local intranet. PWS is one of the best servers available for helping to get you up and running quickly.

18. Personal Web Server Cont… Wizards are included to guide you through the process of setting up home pages and sharing files, and the PWS administrator reduces the complexity of actually running the Web server itself. One of the best uses for PWS is as a platform for testing out Web sites on your Windows 95/Windows NT Workstation computers before hosting them on the Internet This allows you to check the validity of links, scripts, and applications as well as to ensure that the overall organization of the site is functioning correctly

19. Personal Web Server Cont… The server does include support for Active Server Pages (ASP), script debugging PWS presents the ability to develop transactional Web applications using the Microsoft Transaction Server No UNIX version, Lacks some of the more advanced features included with IIS, Only runs on Windows 95/98/ME Windows NT Workstation, Slower than IIS

20. H/W Requirements For Intel-based Windows95/98/ME, Windows NT 4.0 Workstations Intel 486 33 MHz minimum /Pentium 133 MHz recommended 16 MB RAM minimum / 32 MB RAM recommended 40 MB of free HDD Space for installation

21. Personal Web Server Installation Down load PWS from the site http://www.microsoft.com/msdownload/ntoptionpack/askwiz.asp Run setup program and follow the instructions

23. Apache Web Server Apache remains the king of Web servers despite intense efforts by Microsoft and Netscape to gain dominance in the market Its cross-platform support, protocol support (HTTP/1.1), modularity (API), security, logging, and overall performance and robustness Apache runs on Windows (95/98/NT), OS/2, and all the major variants of Unix