Apache is an open-source web server software that is very popular, secure, fast and reliable. It became the first web server to serve over 100 million websites. Apache relies on text configuration files like httpd.conf to manage settings and is run from the command line using a control script. It supports features like SSL, virtual hosts and CGI and can be installed on Linux, Unix and Windows systems.

2. In 2009 it became the first web server software to surpass the 100 million web site milestone.

3. Apache is the most popular web server on the net.

4. It is very secure, fast, and reliable.

5. The name "Apache" derives from the word "patchy" that the Apache developers used to describe early versions of their software.

7. Customized responses to errors and problems

8. Virtual Hosts

9. Multiple DirectoryIndex directives

10. It has been tested thoroughly by both developers and users.

11. APACHE WEB SERVER The Apache Web server provides a full range of Web server features, including CGI, SSL, and virtual domains. Apache also supports plug-in modules for extensibility.

13. IIS

14. SSL

15. The Apache Web server has been ported to Windows and other network operating systems (NOS). The Apache HTTP Server is web server software notable for playing a key role in the initial growth of the World Wide Web.

17. It provides a standard for Web browsers and servers to communicate.

18. The definition of HTTP is a technical specification of a network protocol that software must implement.

19. HTTP is an application layer network protocol built on top of TCP. HTTP

21. The three main HTTP message types are

22. GET, POST, and HEAD.

23. HTTP utilizes TCP port 80 by default

24. Though other ports such as 8080 can alternatively be used.

25. The HTTP also includes

26. ARP

27. DHCP

28. FTP

30. ARP is a low-level network protocol, operating at Layer 2 of the OSI model.

31. ARP usually is implemented in the device drivers of network operating systems.

32. It is most commonly seen on Ethernet networks, ATM, Token Ring, and other physical networks.

34. DHCP is a protocol that assigns unique IP addresses to devices, then releases and renews these addresses as devices leave and re-join the network.

36. FTP is a simple network protocol based on Internet Protocol.

38. SSL security technology helps to improve the safety of Internet communications.

39. SSL is a standard for encrypted client/server communication between network devices.

40. A network protocol, SSL runs on top of TCP/IP.

42. CONFIGURATION Instead of using a point-and-click graphic user interface (GUI) or Windows Registry keys as most other modern software packages, Apache generally relies on simple text files for its configuration settings.

44. srm.conf for resource settings

45. access.conf for security settings

47. The httpd.conf is treated as the "master" configuration file and it contains all of the settings.

48. Both srm.conf and access.conf still exist in the installation, but they contain no settings and are empty except for some comments.

49. Like many UNIX-style programs, Apache will not re-read the .conf files after the Web server starts running.

50. After making changes, an administrator must restart Apache for the new settings to take effect.

52. These entries appear as follows in the file:

53. ServerName compnetworking.about.com Port 80

54. The term "httpd" stands for HTTP Daemon .

56. The most useful of these entries is ServerAdmin -- it allows the administrator to set the email address that will be displayed on error pages (such a "404 pages") in the client's browser, giving users a way to contact someone if a site problem occurs: ServerAdmin compnetworking.guide@about.com

58. It is configured to run standalone for better performance for incoming HTTP requests from client web browsers.

59. A shell script wrapper is included to make starting, stopping, and restarting the server as simple as possible.

60. To start up Apache for the first time, just run:

61. # /usr/local/sbin/apachectl start

63. # /usr/local/sbin/apachectl stop

64. After making changes to the configuration file for any reason, you will need to restart the server:

65. # /usr/local/sbin/apachectl restart

66. To restart Apache without aborting current connections, run:

67. # /usr/local/sbin/apachectl graceful

69. the mime.types file,

70. and the family of log files.