Difference between the HTTP andHTTPs

HTTP stands for HyperText Transfer Protocol, which is just a fancy way of saying it's a protocol (a language, in a manner of speaking) for information to be passed back and forth between web servers and clients.

You really don't need to know what it all stands for; the important thing is the letter S which makes the difference between HTTP and HTTPS. The S (big surprise) stands for "Secure". You probably didn't need me to tell you that, because you already knew it had something to do with security.

If you visit a website or webpage, and look at the address in the web browser, it will likely begin with the following: http://. This means that the website is talking to your browser using the regular 'unsecure' language. In other words, it is possible for someone to "eavesdrop" on your computer's conversation with the website. If you fill out a form on the website, someone might see the information you send to that site.

This is why you never ever ever enter your credit card number in an http website!

But if the web address begins with https://, that basically means your computer is talking to the website in a secure code that no one can eavesdrop on.

You understand why this is so important, right? If a website ever asks you to enter your credit card information, you should automatically look to see if the web address begins with https://. If it doesn't, there's no way you're going to enter sensitive information like a credit card number!

It should be pointed out that just because a website has that magic "S" in its address, that does not mean it is wise to do business with them; even scam artists can have https sites! It simply means that no outsiders can eavesdrop on your conversation...doesn't mean you should be having the conversation in the first place. Only do business with reputable firms, or firms you have thoroughly checked out!

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classification of operating system

Classification of Operating Systems  

Operating systems can be divided broadly into four types, based on the computers they control and applications they support.

Real time O S :

       This type of operating systems are used to control Scientific devices and similar small instruments where memory and resources are crucial. These type of devices have very limited or no end user utilities , so more effort should go into making the OS really memory efficient and fast (less coding), so as to minimize the execution time ,in turn saving on power as well.

E x : VHDL, 8086 etc.

   Image of Xilinx processor for which VHDL code is extensively used as operating system

Single User single Task:
       This type of OS is just better version of Real time OS ,where one User can use the computer to do one thing at a time, which means that doing thing more than one thing at a time is difficult in this type of OS. The handhelds or the palmtop computers are good examples of this type of systems.
E x : Windows mobile etc.
  The look of windows mobile being decorated in a mobile Phone cum PDA. Ref


Single User Multi Task:
      This is the most common type of operating system used today. Microsoft windows and Apple Macintosh are the living examples of this Genre. These can perform Multi tasking operations, like for example playing a multimedia file, downloading a file from the internet and editing a Text file simultaneously.
E x: Windows vista, Mac X tiger etc.
       Typical look of windows screen
Multi User :
         This type of operating systems allow multiple users to use the system resources simultaneously. This should not be confused with the multi user accounts in windows  or similar, the main difference being, the network administrator is the only actual user in Windows or Macs and one more difference being that in OS like Unix more than one user can simultaneously login while this is not possible in windows.
   E x: Unix, Linux, Solaris etc..
The look of a linux screen

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