The document discusses various topics related to web servers including their basic functions, components, common types of websites, client-server architectures, static vs dynamic content, server-side scripting technologies, request messages, and multi-tier architectures. It also covers operating system tasks and mentions Linux as an open-source operating system option.

2.  Web server basics
 Software for Web servers
 E-mail management and spam control issues
 Internet and Web site utility programs
 Web server hardware
2

3.  The main job of a Web server is to respond to
requests from Web client computers
 There are 3 components of a Web server:
◦ Hardware
◦ Operating system software
◦ Web server software
3

4.  Development sites: Used to evaluate different Web designs
 Intranets: Corporate networks that house internal memos,
corporate policy handbooks, and a variety of other corporate
documents
 Extranets: Intranets that allow authorized parties outside the
company to access information stored in the system
 Transaction-processing sites: Commerce sites that must be
available 24 hours a day, seven days a week
 Content-delivery sites: Deliver content such as news, histories,
summaries, and other digital information
4

5.  Client/server architectures
◦ Client computers request
services
◦ A server processes the clients’
requests
 Web software is platform
neutral, meaning that it lets
different types of servers
communicate with a variety of
clients
5

6.  Dynamic content is nonstatic information
constructed in response to a Web client’s request
◦ Dynamic page: Web page whose content is shaped by a
program in response to user requests
◦ Static page: An unchanging page retrieved from disk
6

7.  Server-side scripting (or includes)
◦ Programs running on a Web server create Web pages
before sending them back to the requesting Web clients
 Dynamic page-generation technologies: Server
side scripts are combined with html tags to create
dynamic content
◦ Active Server Pages (ASP)
◦ JavaServer Pages (JSP)
◦ PHP: Hypertext Preprocessor (PHP)
7

8.  Server
◦ Computer used to provide files or make programs
available to other computers
 Server software: Used by a server to make files and programs
available to other computers
 Database server: Server on which database management software
runs
8

9.  Two-tier client/server architecture has one client
and one server
9

10.  Request message: Message that a Web client sends to
request a file or files from a Web server
◦ Typical request message contains:
 Request line
 Contains a command, the name of the target resource, and the
protocol name and version number
 Request headers
 Can contain information about types of files that the client will accept
in response to a request
 Entity body
 Used to pass bulk information to the server
10

11.  Three-tier architecture
◦ Extends two-tier architecture to allow additional processing (e.g.,
collection of data from a database) before reponses to requests are
made
 N-tier architectures
◦ Higher-order architectures
◦ Third tier includes software applications that interactively supply and
update information to and from the web server
11

12. 12

13.  Operating system tasks include running programs
and allocating computer resources
◦ Open-source software: Developed by a community of
programmers who make it available for download at no cost
 Linux: Open-source operating system that is easy to install, fast,
and efficient
13