Week 1:
* Course: Web Applications-PHP
* Course Book: The Missing Link Chapters 1,3,4
* Teacher: Charles Russell Severance
* Free Course Videos: Web Applications for everybody

This is the notes taken by myself, they may be hard to read. You may consider taking the course youself by clicking the links above.

Basic Definations

PHP
PHP is the most widely used scripting language1 , for most web programming. PHP extends HTML pages by adding server executed code segment to HTML pages. The output is merged into HTML page.

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MySQL
SQL stands for Structured Query Language. MySQL is one of the most popular free and open source data base engines in the market place. It powers up dynamic website. The language standard comes from NIST2.

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Javascript
* C like programming language. * Can be included in an HTML webpage. * Allows embed dynamic elements. * Run in the browser.

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JQuery
Elegant way to select DOM elements and register events. It works in different browsers.

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JSON(JS Objective Notation)
A language which is easy for human to read or write, used in transforming information.

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DOM(Document object model)
* Seperate a text document into many editable obejects * Build a connnection between HTML document and programs

Request/Response Cycle

HTTP

HTTP stands for HyperText Transfer Protocal

HTTP Request/Response Model

HTTP Request/Response Model

URL

URL stands for Uniform Resource Locator

Parts of a URL

Parts of a URL

Clicks on an anchor tag with an href="" to switch to anthor page. The browser makes a connection and issues an “GET” request.
The server then returns a HTML document. The Browser renders the doc and display it on screen. A simple URL tag example: <a href="example.com"> Text hint here </a>.

Making an HTTP request

An example of HTTP/1.0 response

An example of HTTP/1.0 response

Nowadays, few and few servers support HTTP/1.0.(At least 1.1)

Other things

Reserved IP Address (IPv4)

Reserved IP is some ip which can’t be used in WAN.

IP Addresses Usage
127.X.X.X A loop back address to local machine
0.X.X.X Use for communications between processes in local machine
10.X.X.X Used in communication in a private network (e.g. LAN)
192.168.X.X Used in communication in a private network (e.g. LAN)

NAT (Network Address Translation)

The function of NAT is to translate between public IP address and private IP address.

How NAT works

How NAT works

Subnet Mask

To fully understand Subnet Mask, please view another article.

English: Subnet Mask

正體中文: 子網掩碼


  1. A scripting language is a programming language that is interpreted, meaning it is translated into machine code when the code is run , rather than beforehand. Scripting languages are often used for short scripts over full computer programs. JavaScript, Python, and Ruby are all examples of scripting languages.
  2. National Institute of Standards and Technology. NIST’s mission is to promote U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve our quality of life.