Web programming Lecture # 3

2 Revision of last class

Introduction of Web Programming

Introduction

HTML, XHTML, DHTML and HTML5

CSS and CSS3

Client side script

Server side script

Web Server

Database

Client

Client Server Architecture

Two tier

Three tier

3 Revision of last class Cont...

Web Developing V/s Web Designing

Web Developer V/s Web Designer

4 Web architecture & http

History of the World Wide Web ( www )

Overview of Hyper Text Transfer Protocol ( http )

Internet v/s Web

5 History of the World Wide Web ( www )

The Advanced Research Projects Agency Network (ARPANET) was one of the world's first operational packet switching networks, the first network to implement TCP/IP, and the progenitor of what was to become the global Internet. The network was initially funded by the Advanced Research Projects Agency (ARPA, later DARPA) within the U.S. Department of Defense for use by its projects at universities and research laboratories in the US. The packet switching of the ARPANET, together with TCP/IP, would form the backbone of how the Internet works.

6 History of the World Wide Web ( www )

In 1990 and 1991,Tim Berners-Lee created the World Wide Web at the European Laboratory for Particle Physics (CERN) in Geneva, Switzerland

The original purpose of the World Wide Web (WWW) was to provide easy access to cross-referenced documents that existed on the CERN computer network.

7 World wide Web

Hypertext linking allows you to quickly open other Web pages

A document on the Web is called a Web page

A Web page is identified by a unique address called the Uniform Resource Locator (URL)

A URL is also commonly referred to as a Web address

A URL is a type of Uniform Resource Identifier (URI)

A Web site refers to the location on the Internet of the Web pages and related files

Web pages are displayed using a program called a Web browser

A Web server is a computer that delivers Web pages

The most popular Web server software is Apache HTTP Server (Apache)

The second most popular Web server is Microsoft Internet Information Services (IIS) for Windows

8 HTML Versions

9 Hyper Text Transfer Protocol ( http )

It's the protocol used to allow you to communicate with web sites.

HTTP functions as a request-response protocol in the client-server computing model. A web browser, for example, may be the client and an application running on a computer hosting a web site may be the server. The client submits an HTTPrequest message to the server. The server, which provides resources such as HTML files and other content, or performs other functions on behalf of the client, returns a response message to the client. The response contains completion status information about the request and may also contain requested content in its message body.

10 Hyper Text Transfer Protocol Secure ( https )

It's the protocol used to allow you to communicate with web sites.

https= http + SSL

SSL= Secure Socket Layer

It means that information exchanged between you and a web site is encrypted and cannot be hijacked by someone who might want to electronically eavesdrop when you type a credit card number, a password, a social security number, or any other person information.

The purpose of the email is to encourage you to check for the "HTTPS" before you give financial information.  Most web sites are not HTTPS, but when you click a link to make a purchase, many of them will direct you to an HTTPS site.

11 Hyper Text Transfer Protocol Secure ( https )

12 http v/s https

Http

URL begins with http://

No encryption

Unsecured

Operates at Application Layer

https

URL begins with https://

Encryption is present

Secured

Operates at Transport Layer

13 Links for Notes

https://sites.google.com/site/neisa1207/