Download Bits 2513 internet technology

What is WWW
o WWW (WORLD WIDE WEB)
 A network of information resources
The web relies on three mechanisms to make these resources readily
available to widest possible audience:
1.
2.
3.
A Uniform Naming Scheme for locating resources on the web (e.g
URIs)
Protocols for access to named resources over the web (e.g HTTP)
Hypertext for easy navigation among resources (e.g HTML)
TERMS AND DEFINITIONS
• WEB BROWSER (web client, called a browser)
 Is the software that allow to interact with information available on the internet
• HTML (HYPERTEXT MARKUP LANGUAGE)
 A tagging languages used to compose documents that will be viewed by a web browser
• WEB PAGE
 A mixture of text, graphics, sound and animation the html format, to make information
accessible in a easy to understand format using the internet.
• WEB SITE
 A collection of web pages connected (linked) by hypertext clickable links.
TERMS AND DEFINITIONS
• WEB SITE STORAGE / HOSTING
 After a web site is designed it must be stored on a computer that can be accessed through the internet
and the World-wide Web
• World-Wide Web
 WWW is a pair of software application, which allow both distribution of and access to information on the
internet.
 The web is not the internet BUT, a means of distributing and accessing the information that is on it.
• E-COMMERCE / E-BUSSINESS ( Electronic Commerce or EC)
 Is the buying and selling of goods and services on the internet, especially on the World-Wide Web.
• HTTP ( Hypertext Transfer Protocol)
 Is the set of rules for exchanging files (text, graphic image, sound , video, and other multimedia files )
on the World-Wide Web.
WEB PAGE
• KNOWN AS HTML (HYPERTEXT MARK-UP LANGUAGE) DOCUMENT ACCESSIBLE ON THE WORLD
WIDE WEB
• WEB PAGES CAN BE STATIC, DYNAMIC OR ACTIVE
• STATIC PAGES
 Are fixed-content documents that are created and stored in a server. thus, show the
same content each time they are viewed. ( E.g bold word )
• DYNAMIC PAGES
 Have content that can change each time they are accessed. these pages are written in
scripting languages which run functions on the server that return information ( E.g, date)
• ACTIVE PAGES
 Are programs or scripts to be run at the client side ( E,g Applets, Scripts, Plug-in)
How web page works
SAMPLE WEB PAGE AND ITS SOURCE.
•
THE SOURCE CONTAINS THE INSTRUCTIONS THAT DEFINE THE CONTENTS,
LAYOUT, AND STRUCTURE OF A WEB PAGE.
• THE INSTRUCTION ARE WRITTEN IN HTML OR ANOTHER WEB AUTHORING TOOL
USED IN CREATING THE PAGE
• THE BROWSER USES THESE INSTRUCTIONS TO INTERPRET AND DISPLAY THE
WEB PAGE ON THE SCREEN
How the WEB works
1. USER SENDS REQUEST
2. BROWSER INTERPRETS
USER’S SELECTION AND
MAKE REQUEST TO SERVER
5. USER RECEIVES FILE
DESPLAYED BY THE BROWSER
4. SERVER SENDS
REQUESTED FILE
TO BROWSER TO
BE INTERPRETED
3.SERVER ACCEPTS
AND PROCESSES
REQUEST FROM
BROWSER
PROGRAMMING LANGUAGES
 Used to write software, process Web forms, fetch and
display data, and perform all kinds of advanced
functions.
TYPE OF PROGRAMMING
LANGUAGES
DESCRIPTIONS
CGI (Common Gateway Interface)
• CGI program can be written in any programming languages, including C, Perl,
and Visual Basic Script (VBScript).
• Commonly used to process a form on a Web page.
ASP (Active Server Pages)
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.NET framework
• Developed by Microsoft
• More powerful than ASP for writing applications for the Web
PHP
• Server-based language.
• Frequently the language used to write open source
• PHP functionality can be installed on Windows servers, it is native to Linux server
environment and commonly used there.
Developed by Microsoft
A programming environment that processes scripts on a Web server.
Often use for scripting.
End in the file extension .asp
TYPE OF PROGRAMMING
LANGUAGES
DESCRIPTIONS
Java/Java Applets
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JavaScript
• A very popular programming language created by Netscape
Communications.
• Small programs written in this language are embedded within a Web page,
or fetched externally from within the page, to enhance the page’s
functionality.
XML
• XML (eXtensible Markup Language) is a mark-up language that enables
Web designers to create customized tags to provide functionality not
available with HTML alone.
AJAX (Asynchronous JavaScript and
XML)
• Used to create interactive Web applications.
SQL (Structured Query Language)
• Focuses on extracting data from databases.
• Some Web sites are created extensively or entirely from data stored in
database tables.
Developed by Sun Microsystems
Similar to C++
Can be used to write applications for both Web and non-Web use.
Usually in form of Java servlets.
A Web page that links to a Java servlet has the file extension .jsp
Cascading Style Sheets
• Cascading Style Sheets (CSS), developed by the World Wide Web Consortium (W3C), is a feature of HTML
that makes it possible to apply consistent formatting to the HTML documents in a Web site.
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CSS helps Web developers separate the design of a Web site from the content included in the Web site.
CSS work by controlling how the information on a Web page or entire Web site is displayed.