- Positioning: Is some what where we need the object to be placed in the graphical view i:e on screen. If we talk in DHTML sense then we have two types of positioning: Relative and Absolute.

Relative Positioning: Relative positioning is the same as the current HTML3 layout and is best reserved for situations where you want to be sure that the content will revert to this default inside a document that also uses absolute positioning.

Absolute Positioning: In DHTML absolute positioning means that the object will remain at the same position regardless of the condition of other elements and the size of the browser. In simple languages if an object/image is absolutely positioned (STYLE="position: absolute;"), with an offset of 150 pixels to the right and 250 pixels down from the left-hand corner of the browser screen then it will avail this position what ever the circumstances may be.

- Style Modifications: Style modification indicates the changes in the presentation or the view part that are being made in web page. This part comes under Cascading Style Sheet where the user style his web page by using the attributes and the tags that are pre-defined in CSS.

- Event Handling: As explained earlier Events is the beating heart of any JavaScript application. For handling event in DHTML we attach event handler to HTML elements. The event handler waits until a certain event, for instance a click on a link, takes place. When it happens it handles the event by executing some JavaScript code that has been defined by us. After it has executed the code the event handler comes to its initial state and waits for the user to fire any event. Hence to handle events in DHTML we need to register an event handler.

- B2B (Business-to-Business)   :

In B2B, companies transact with each other. This includes the companies selling their product to wholesalers, distributors, etc

- B2C (Business-to-Consumer) :

This is usually when average businesses transact with the customer. This is done through the shopping cart softwares and the amount involved in the transactions is usually low.

- C2B (Consumer-to-Business) :

In this, a consumer places the product on the net. The companies willing to buy this product bid for it. The comsumer can then decide, depending upon the bid, which company to sell it to. 

- C2C (Consumer-to-Consumer):

These kind of transactions are usually done at an individual level. Payments can be done with the help of online systems like PayPal.

- Web browser supports HTTP secure method that allows more security for the sites that are involved in day to day basis transaction. 

- Security offers quick and easy way to remove the unwanted material or the things that are stored without permission like cache, cookies and history. 

- Security is being provided by the use of blockers that blocks unwanted access to the websites from the outside. 

- Web browser uses other features like disabling of JavaScript and pop up blockers to block any unwanted scripts or messages to run on the system.

- Web browser also uses the security concerns in regard of blocking the access to the secure sites that provides money transfer facilities, etc.

There are two major platforms that providing hosting and servers to host on. The differences between them are as follows:

- Unix are more efficient in performing offsite and onsite, whereas windows doesn’t provide very good efficiency to work with. 

- Unix provide lower hosting cost for the website using the high bandwidth, whereas windows take more resources and have the cost higher for the storage. 

- Unix is better for the websites that are static and includes HTML and graphics, whereas Windows is used for heavy websites and having more requirements. 

- Unix supports the scripting languages like PHP and databases like MySQL and other related categories, whereas Windows supports IIS, coldfusion and big applications that take more space.

The XML DOM (document object model) is used the access and management of xml. It is a platform that is language neutral and allows a program or a script to dynamically access a document. It also allows the updation of content as well as the structure and style of the document. It is responsible for the defining of the object and properties of all xml elements as well as to define the methods for their access. There are various methods that can be used in xml dom such as:

- getElementsByTagName: used to call a specific user defined tag.

- setAttribute: used to change the value of an existing attribute.

- appendChild: used to add a child node to another node.

Math object has two constant : Math.PI and Math.E

Math object has following functions:

- Math.abs(val1);

It will give absolute value of val1.

- Math.max(val1,val2);

This fuction will return maximum value from val1 and val2.

- Math.random();

This function will return a random number between 0 and 1.

- Math.floor(val1)

This function will returns decimal value of val1

Files can be read and written by using java script functions – fopen(),fread() and fwrite().

The function fopen() takes two parameters – 1. Path and 2. Mode (0 for reading and 3 for writing). The fopen() function returns -1, if the file is successfully opened.

Ex: file=fopen(getScriptPath(),0);

The function fread() is used for reading the file content.

Ex: str = fread(file,flength(file));

The function fwrite() is used to write the contents to the file.

Ex(): file = fopen("c:\MyFile.txt", 3);// opens the file for writing

fwrite(file, str);// str is the content that is to be written into the file.

Windows object is top level object in Java script. It contains several other objects such as, document, history, location, name, menu bar etc., in itself. Window object is the global object for Java script that is written at client-side.

Information pertaining to the client browser and system is returned by the navigator object of JavaScript. Navigator object is the top level object for all users.