Web Applications

Internet & web

Internet = largest network in the world that connects people/organization all over the world.

Web = contains hypertext links, or highlighted keywords and images that lead to related information.

Web Applications

What is Web Application?

A web application is any application that uses a web browser as a client. The application can be as simple as a message board or a guest sign-in book on a website, or as complex as a word processor or a spread sheet.

What are the examples of Browsers?

Safari

Mozilla Firefox

Google Chrome

Internet Explorer

Client side scripting + Server side scripting = Web Apps

There are two types of web applications. They are static web and dynamic web.

What is Static Web?

A static web page (sometimes called a flat page/stationary page) is a web page that is delivered to the user exactly as stored, in contrast to dynamic web pages which are generated by a web application.

Consequently a static web page displays the same information for all users, from all contexts, subject to modern capabilities of a web server to negotiate content-type or language of the document where such versions are available and the server is configured to do so.

Static web pages are often HTML documents stored as files in the file system and made available by the web server over HTTP. However, loose interpretations of the term could include web pages stored in a database, and could even include pages formatted using a template and served through an application server, as long as the page served is unchanging and presented essentially as stored.

Dynamic Web

A dynamic web page is a web page with web content that varies based on parameters provided by a user or a computer program.

Generation of the web

1^st generation Web 1.0

Web 1.0 was an early stage of the conceptual evolution of the World Wide Web, centered around a top-down approach to the use of the web and its user interface. Socially,[clarification needed] users could only view webpages but not contribute to the content of the webpages. According to Cormode, G. and Krishnamurthy, B. (2008): "content creators were few in Web 1.0 with the vast majority of users simply acting as consumers of content." Technically, Web 1.0 webpage's information is closed to external editing. Thus, information is not dynamic, being updated only by the webmaster. Economically, revenue generated from the web was made by concentrating on the most visited webpages, the head and software's cycle releases. Technologically, Web 1.0 concentrated on presenting, not creating so that user-generated content was not available.

Examples: Informational Website, Company Website

 

2^nd generation Web 2.0

The term Web 2.0 was coined in 1999 to describe web sites that use technology beyond the static pages of earlier web sites. It is closely associated with Tim O'Reilly because of the O'Reilly Media Web 2.0 conference which was held in late 2004. Although Web 2.0 suggests a new version of the World Wide Web, it does not refer to an update to any technical specification, but rather to cumulative changes in the ways software developers and end-users use the Web.

A Web 2.0 site may allow users to interact and collaborate with each other in a social media dialogue as creators of user-generated content in a virtual community, in contrast to websites where people are limited to the passive viewing of content. Examples of Web 2.0 include social networking sites, blogs, wikis, video sharing sites, hosted services, web applications, mishaps and folksonomies.

Whether Web 2.0 is substantively different from prior web technologies has been challenged by World Wide Web inventor Tim Berners-Lee, who describes the term as jargon. His original vision of the Web was "a collaborative medium, a place where we all meet and read and write".

3^rd generation Web 3.0

This will be about semantic web (or the meaning of data), personalization (e.g. iGoogle), intelligent search and behavioral advertising among other things.

If that sounds confusing, check out some of these excellent presentations that help you understand Web 3.0 in simple English. Each takes a different approach to explain Web 3.0 and the last presentation uses an example of a "postage stamp" to explain the "semantic web".

Categories of web 2.0 sites

Online social networking

Mashups and aggregators

Online social networking

Usually involved websites that are known as social sites.

Social networking websites function like an online community of internet users.

Advantages :

Online community members could share common interests in hobbies, religion, or politics.

Can socialize with the members

Can make friends from all over the world and learn a thing or two about new cultures or new languages and learning is always a good thing.

Examples of social sites:  My Space, Twitter, Facebook

 

Aggregators

Aggregate means= collects things together

Aggregator

            -  is a web site that takes different content from a number of other web sites and mixes them together to create a new kind of content.

            - mix and match content form other parts  of the web

Includes:

            - data aggregator

            - video aggregator

            - social network aggregator

            - search aggregator

            - news aggregator

Web 2.0 IT and Applications

What is programming language?

- A set of words, abbreviations, and symbols that enables a programmer to communicate the instructions to a computer.

- A language for a programmer used to communicate with a computer.

What are the programming languages?

XML & AJAX

Types of PL

Low-level-language

High-level-language

Machine language

Sometimes referred to as machine code or object code, machine language is a collection of binary digits or bits that the computer reads and interprets. Machine language is the only language a computer is capable of understanding.

E.g-

004a 8b 45 e0

004d 89 45 f8

0050 89 45 ec

0053 8b 45 ec

0056 89 45 f8

0059 8b 45 e0

005c ba 00 00 00 00

0061 f7 7d f8

0064 03 45 f8

0067 d1 f8

0069 89 45 ec

006c 3b 45 f8

006f 75 e2

0071 8b f4

Assembly language

Sometimes referred to as assembly or ASL, assembly language is a low-level programming language used to interface with computer hardware. Assembly language uses structured commands as substitutions for numbers allowing humans to read the code easier than looking at binary. Although easier to read than binary, assembly language is a difficult language and is usually substituted for a higher language such as C. Below, is an example of assembly language in a debug routine.

Third generation language

Third-generation languages (3GLs) are the first to use true English-like phrasing, making them easier to use than previous languages.

It is also known as Procedural languages.

Fotrun, COBOL, Basic, Pascal are 3^rd GL.

Fourth generation language

It is known as non-procedural language.

4GLs may use a text-based environment (like a 3GL) or may allow the programmer to work in a visual environment, using graphical tools.

VB & Visual Age are 4^th GL.

5^th generation language

This is Object-oriented and Web development tools

Example : Prolog, AJAX, JAVA Script

XML= Extensible Markup Language

            - Markup Language for Web Documents (2.0)

            -  contains structured information including words and pictures

            - Example:

                        <chapter>Hardware

                        <Topic >Input Device

                       

                        <h1>Hardware                                   

                        <body >Input Device               html

AJAX= acronym referring to Asynchronous JavaScript and XML

Java Script=   - Script/Language

            - Object Oriented Programming Language based on C++                                programming language.

            - used the client-side techniques to create web application

                       

  Some examples of web pages using AJAX is: Youtube, Gmail, Google  Maps and most of web 2.0 website.

Tagging

            - it is about metadata

            - it is part of the  nature of Web 2.0

            - Keyword for a piece of information in Web (Describe the item)

Blogs

            - short for weblog

            - it is informal website (articles, diary, journal)

            - a shared on-line journal where people can post diary entries about their personal experiences and hobbies

Wiki

            - collaborative website that allows users to create, add, modify or delete              website content via their web browser.

            - Many wikis are open to modification by public

            - A popular wiki are Wikipedia and Web encyclopedia

RSS (RSS 2.0)

            - Really Simple Syndication

            - RSS is a technology that is being used by millions of web users around the world to keep track of their favourite websites.

            - application of aggregators

            - Examples RSS Reader= Google reader, Blog lines

                       

Podcasting and Video casting

            -  Digital media consist of (audio, video)

            - Technology in web 2.0

- download/upload digital media (online)

              For example: use the iTunes free software to subscribe to a specific podcast.

What is Google apps?

Applications and Infrastructure.  “A series of applications from Google”.

Google application technology

• Messaging
• Calendaring
• Documents
• Video
• Sites
• Talk

What is G-Mail?

It encourages users to communicate.

IM, voice and video chat

 Anytime, anywhere access to your email.