Two Marks Internet Programming

31. What do you mean by Server-side?

Occurring on the server side of a client-server system. For example, on the World Wide

Web, CGI scripts are server-side applications because they run on the Web server. In contrast,

JavaScript scripts are client-side because they are executed by your browser (the client). Java

applets can be either server-side or client- side depending on which computer (the server or

the client) executes them.

32. What is a protocol?

An agreed-upon format for transmitting data between two devices. The protocol

determines the following:

1.The type of error checking to be used

2.Data Compression method, if any

3.How the sending device will indicate that it has finished sending a message

4.How the receiving device will indicate that it has received a message

There are a variety of standard protocols from which programmers can choose.

Each has particular advantages and disadvantages; for example, some are simpler than

others, some are more reliable, and some are faster. The protocol can be implemented

either in hardware or in software.

33. What is ActiveX?

A loosely defined set of technologies developed by Microsoft for sharing information

among different applications. ActiveX is an outgrowth of two other Microsoft technologies

called OLE (Object Linking and Embedding) and COM (Component Object Model). As a

moniker, ActiveX can be very confusing because it applies to a whole set of COM-based

technologies. Most people, however, think only of ActiveX controls, which represent a

specific way of implementing ActiveX technologies.

34. Write a note on ActiveX controls.

A control using ActiveX technologies. An ActiveX control can be automatically

downloaded and executed by a Web browser. ActiveX is not a programming language, but

rather a set of rules for how applications should share information. Programmers can

develop ActiveX controls in a variety of languages, including C, C++, Visual Basic, and

Java.

An ActiveX control is similar to a Java applet. Unlike Java applets, however, ActiveX

controls have full access to the Windows operating system. This gives them much more

power than Java applets, but with this power comes a certain risk that the applet may

damage software or data on your machine. To control this risk, Microsoft developed a

registration system so that browsers can identify and authenticate an ActiveX control

before downloading it. Another difference between Java applets and ActiveX controls is

that Java applets can be written to run on all platforms, whereas ActiveX controls are

currently limited to Windows environments. Related to ActiveX is the scripting language

VBScript that enables Web authors to embed interactive elements in HTML documents.

35.Explain about HTTP Connection.

It is a communication channel between web browser and web server. It begins on the

client side with the browser sending a request to the web server for a document.

Request Header Fields are

1. From

2. Reference

3. If_modified_since

4. Pragma

5. User Agent