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What is Common Gateway Interface (CGI)

The Common Gateway Interface ( CGI ) is an accepted standard for interfacing Web servers and external applications. Web servers and external applications. Web servers were originally designed to serve static HTML documents along with other associated static files. A WEb browser that communicates with a Web server limits its functionality to serving static pages. it displays only documents whose contents will not change between requests or during page visualization. However, CGI established a standard for information to be exchanged between Web servers and browsers. CGI allows the passing of information between a browser or server to an external program that performs some actions. it then outputs its results back to the user's browser. CGI ( Common Gateway Interface ) is a standard whose specification defines a way for Web servers to communicate with external programs, and vice versa. with this method, the external program can generate HTML, images, etc. for the server for its pr

Virtual Reality Modeling Language - Digital Communication

Virtual worlds are created using a computer language called Virtual Reality Modeling Language ( VRML ). this language instructs computers on how to build 3D geometric objects . VRML is a 3D equivalent to HTML, but with more capabilities than just putting a 3D shop on your web page. Imagine the Internet as a place where you could walk through three-dimensional worlds. you will pick up objects, examine them and go to other internet locations by flying or walking through doors. what happens if you could be inside 3D flats , just like you can walk through a city or a building. This is all that we call virtual Reality ( VR in short). you will find many virtual worlds you can explore on the Internet. you will be able to walk through a giant computer, explore bizarre art galleries, visit outer space, go to the sites of what seem like ancient ruins, explore inside the human brain. The future of the Internet may be seen in the evolving 3D formats with which real or imaginary spaces are dep

Introduction to Multimedia - Digital Communication

A very dramatic and remarkable part of the Internet is its multimedia capability. Listening to music sounds clips and live radio stations from your computer, make you enjoy the capability of the Internet. Using your computer and Internet together has made you listen to live concerts being broadcasted somewhere on the Internet. and you can even have a live video conference with people from anywhere in the world. for all this, you do not need specialized hardware and software. Also, note that the Internet's multimedia capabilities go beyond the more playing of audio and video clips. you can participate in virtual worlds and join in "virtual chat" sessions in which you build your own online persona, called an avatar, which communicates with other avatars. the internet allows for the creation of remarkable online multimedia content , combining animation , sound , and programming using VRML and Macromedia's Shockwave . Sending Audio Files on the Internet In Video Confer

What is CRYPTOGRAPHY and its Types - Digital Communication

In networking and telecommunications , the data transmitted over a network in such a way that if the data is captured but it cannot be read by unauthorized users. What is Cryptography? Cryptography is the science of information security. it is closely related to the disciplines of cryptology (it is the mathematics, such as a number theory and the application of formulas and algorithms) and cryptanalysis (it refers to the study of ciphers, ciphertext with a view to finding weaknesses in them that will permit retrieval of the plain text from the ciphertext, without necessarily knowing the key or the algorithms). Cryptography includes techniques such as microdots, merging words with images, and other ways to hide information in storage or transit. however, cryptography is most often associated with scrambling plain text (ordinary text) into ciphertext (a process called encryption), then back again (known as description). individuals who practice this field are known as cryptographers. C

Information Privacy & Copyright Issues - Digital Communication

Privacy means the concept in which users ' data such as stored files, e-mail , etc. are not be seen by any other person without the main user's permission. in other words, it is private communication accomplished when the sender and intended receiver can read the message. in this section, important points related to privacy such as E-mail privacy are described. E-Mail Privacy When you send an e-mail, the message is broken into several packets and each packet is sent through the internet. The number of packets depends on the length of the message. each packet that is sent over the internet has the internet address of the sender and the recipient's address. packets of a single message may take different routes to reach the destination. before reaching the destination, messages pass through different systems. This means the content of the message and the address of the sender and receiver are examined by all the systems through which each packet is routed. so, in the absence

Internet Security & Authentication Methods - Digital Communication

When we use a computer system which is connected to the internet we are able to reach different sites. one system which is connected to the internet can be reached to another system by the same protocol . when we download any information from the Internet, our first incentive is about the security of our computer system and another system. the reason for the concern about the system is that we don't want an unauthorized person to access any information from our system. we need to be concerned about the security of another system so that we can conduct business transactions and retrieve faithful information. Maintaining security becomes more important when we use the internet as a commercial transaction. we need to make sure that messages are private and financial transactions are secure. methods of internet security are described: What is Authentication? Authentication is the process of determining the identity of a user who is attempting to access a system. also for security pur

What is Firewall? Three types of Firewalls and benefits - Digital Communication

Firewalls are hardware and software combinations that are built using routers , servers , and a variety of software . they sit at the most vulnerable point between a corporate network and the internet and they can be as simple or complex as system administrators want to build them. firewall reduces the speed of access of networks. Every time a corporation connects its internal computer network or LAN to the Internet, it faces potential danger regarding security. due to the Internet's openness, every corporate network connected to it is vulnerable to virus attacks. crackers on the Internet ould break into the corporate network and do harm in a number of ways. Some such methods are following: They could copy or damage important data. Damage individual computer data or the entire networking. Use the corporate computer's resources or use the corporate network and resources as a way of posing to be a corporate employee. The solution for all these problems and many more is to bu

Internet Security Threats - Digital Communication

Due to the widespread use of PCs and development in networks connecting PCs to company's mainframe computers, there has been an increase in the chances of feeding undesirable data deliberately by outsiders. a person with a PC at a remote place can use a phone line and illegally collect information without leaving any clues. individual users can copy confidential data from a company's computer or their details from a remote station connected via a communication network . Security means preventing the network communication system from falling into the hands of unauthorized people. the sender of data may wish to be assured that only the intended party actually receives designated data. the receiver must authenticate first that it is the one who is authorized to receive data and thereafter the sender exchanges data. Hence, we need to take such steps so as to protect data during transmissions and guarantee that these transmissions are by authorized persons only. What is Computer