RE: INTERNET SECURITY
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Internet is a global collection of networks, both big and small. These networks connect together in many different ways to form the single entity that we know as the Internet. Since it’s beginning in 1969, the Internet has grown from a few host computer systems to tens of millions.
In Internet, dozens of large Internet providers and trillions of bytes of data flow between the individual networks. What is incredible about this process is that a message can leave one computer and travel halfway across the world through several different networks and arrive at another computer in a fraction of a second!
One of the important aspects that has to be taken into account is that It ensures that information doesn't go where it's not needed. This is crucial for keeping large volumes of data from clogging the connections of "innocent bystanders." It makes sure that information does make it to the intended destination.
Internet and its Applications
The term INTERNET has been coined from two terms “INTERCONNECTION” and “NETWORK”. A network is simply a group of computers that are connected together for sharing information and resources. Several such networks have been joined together across the world to form what is called as
Applications of Internet
In its simplest form, we can do the following three things on and using Internet:
1. Access to Information
2. Communicating with people
3. Communicating to other Computer Systems
1. Access to Information: - Internet provides tremendous wealth of information. There are thousands of computer programs and data that have been made available to users. These files may be
Text files, graphic files, sound files, full motion video files or program files. There are several ways we can obtain the desired information:
FTP & Archie: -
Using FTP, user can copy computer files from remote computer to his computer. This is called Downloading. Also, user can send files from his computer to remote computer. This is called Uploading. FTP is standard protocol. It consists of standard set of commands for file downloading and uploading. Remote computer is called FTP Server. There are some special computers called Archie Servers that maintain indexes of what files are stored on FTP Servers around the world and are updated regularly.
WWW: - There is another approach to offering information on computers through Internet called WWW. A www computer system consists of a computer called Web Server. Information that is to be offered is stored on Web Services in the form of Web Pages. User can view these web pages using a Web Browser e.g. Internet Explorer or Netscape or Mosaic. A web page can simply be a block of text, but typically also includes graphics. Sound clips and full motion video might also be part of a page. Anything on this page can be linked to another of / for information.
2. Communicating with People: -
There are many ways by which we can communicate with people on Internet. Some are: -
E-Mail: - User can send text, pictures, sounds, programs or movies to any person on Internet anywhere in the world.
Internet News: -
There are number of Newsgroups on INTERNET. These groups are different from e-mail. Message sent to a newsgroup are simply posted on the electronic notice board. Anyone can see these messages. You can place your own news items or can access the news items placed by others.
Chatting and Conferencing :-
Another communication method called Internet Relay Chat (IRC). Using IRC, you can speak to other users around the world virtually in real time as though you were in same room. Using appropriate software, we can also have audio and Video Conferences.
3. Connecting to other Computer Systems :- We can link to a remote computer via the
INTERNET and gain access to the data and programs stored on it. Computer can be linked to remote computers using other communication media such as Direct Connection using a Cable, but in such cases, the cost of communication is too high and most people cannot afford it. Using an appropriate program i.e. TELNET, an Internet user can use Internet’s transmission medium to connect to other computer systems directly. Once connection is established with remote computer, the user can use that remote computer as if his computer were a hardwired terminal of that system. While acting as a dumb terminal to remote system, Telnet allows the user to do their work without running up high priced long distance charges. The only cost would be your regular fees to your Internet Service Provider.