1. APACHE WEB SERVER

2. Apache
An open source web server. Mostly for Unix, Linux and Solaris platforms
Apache is the most popular web server on the net.
It is very secure, fast, and reliable.
The name "Apache" derives from the word "patchy" that the Apache developers used to describe early versions of their software.

3. Features Implements many frequently requested features, including:
DBM databases for authentication
Customized responses to errors and problems
Virtual Hosts
Multiple Directory Index directives
It has been tested thoroughly by both developers and users.

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

5. Cont.. The Apache Web Server has HTTP IIS SSL
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.

6. HTTP HTTP is an Hypertext Transfer Protocol.
It provides a standard for Web browsers and servers to communicate.
The definition of HTTP is a technical specification of a network protocol that software must implement.
HTTP is an application layer network protocol built on top of TCP.

7. HTTP
HTTP clients (such as Web browsers) and servers communicate via HTTP request and response messages.
The three main HTTP message types are
GET, POST, and HEAD.
HTTP utilizes TCP port 80 by default
Though other ports such as 8080 can alternatively be used.

8. HTTP The HTTP also includes ARP-Address Resolution Protocol
DHCP-Dynamic Host Configuration Protocol
FTP-File Transfer Protocol

9. ARP
ARP converts an Internet Protocol (IP) address to its corresponding physical network address.
ARP is a low-level network protocol, operating at Layer 2 of the OSI model.
ARP is implemented usually in the device drivers of network operating systems.
It is most commonly seen on Ethernet networks, ATM, Token Ring, and other physical networks.

10. DHCP
DHCP allows a computer to join an IP-based network without having a pre-configured IP address.
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.

11. FTP
FTP allows you to transfer files between two computers on the Internet.
FTP is a simple network protocol based on Internet Protocol.

12. IIS
Internet Information Services (IIS) – formerly called Internet Information Server – is a web server application and set of feature extension modules created by Microsoft for use with Microsoft Windows.
IIS 7.5 supports HTTP, HTTPS, FTP, FTPS,SMTP 
and NNTP.
It is an integral part of Windows Server family of products

13. SSL Secure Sockets Layer
SSL security technology helps to improve the safety of Internet communications.
SSL is a standard for encrypted client/server communication between network devices.
A network protocol, SSL runs on top of TCP/IP.

14. SSL
SSL utilizes several standard network security techniques including public keys, symmetric keys, and certificates. Web sites commonly use SSL to guard private information such as credit card numbers.

15. Configuration
Apache uses a system of three text files for managing its configuration data.
All three of these files (almost always) appear in Apache's ./conf directory and are designed to be edited by system administrators:
httpd.conf for general settings
srm.conf for resource setting
access.conf for security settings

16. Configuration
In the most recent versions of Apache, the default installation has changed.
The httpd.conf is treated as the "master" configuration file and it contains all of the settings.
Both srm.conf and access.conf still exist in the installation, but they contain no settings and are empty except for some comments.

17. Cont..
Like many UNIX-style programs, Apache will not re-read the .conf files after the Web server starts running.
After making changes, an administrator must restart Apache for the new settings to take effect.

18. Inside Httpd.conf
The httpd.conf contained general settings such as the ServerName and Port number.
These entries appear as follows in the file:
ServerName compnetworking.about.com Port 80
The term "httpd" stands for HTTP Daemon.

19. Cont..
This file contains a number of other entries (technically called directives), but for most of these, modifications are optional.
The most useful of these entries is ServerAdmin -- it allows the administrator to set the 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

20. Running Apache
Apache does not run from the inetd super server as many other network servers do.
It is configured to run standalone for better performance for incoming HTTP requests from client web browsers.
A shell script wrapper is included to make starting, stopping, and restarting the server as simple as possible.
To start up Apache for the first time, just run:
# /usr/local/sbin/apachectl start

21. Cont.. You can stop the server at any time by typing:
# /usr/local/sbin/apachectl stop
After making changes to the configuration file for any reason, you will need to restart the server:
# /usr/local/sbin/apachectl restart
To restart Apache without aborting current connections, run:
# /usr/local/sbin/apachectl graceful

22. Cont.. The family of .conf files supports most,
but not all of Apache's configuration options.
*Other important mechanisms for managing an
Apache Web server include the
.htaccess file, the mime.types file,and the family of log files.