Difference Between Real Time System and Online System

We are all used to real time systems as we deal with them in all walks of life. We also know what an online system is as surfing is a particular example of online system that is all pervasive today. There are online systems that are almost real time as RTGS which is online system of transfer of funds electronically. When there is so much similarity between online and real time systems, there is bound to be confusion among the minds of readers pertaining to their differences. This article attempts to highlight these differences to remove all confusions.

Online has just one meaning and that is when one is logged on to internet. Whether you are playing a game online, tracking movement of share prices, or talking to your friend via instant messenger, you are effectively dealing with online systems. There are systems that update automatically after a specified time and there are systems where you need to refresh the page manually. There is some time lag between the event that is happening and the time when the web page refreshes. If you are watching a live telecast of a cricket match online, it is not real time as you get to see a wicket falling or a ball being bowled after a lag of a few seconds.

A real time system changes its state as a function of physical time. Some examples of real time systems are command and control systems, defense and space systems, air traffic control systems, automated electronics. Real time systems are not dependent upon just logical results of manual computations but also on the exact instant that the events happen or take place. One example of real time system is when you are chatting with your friend online. You see the reaction of the system as soon as you type in the messenger. Because of advancements in technology and increase in the number of users, many online systems today are almost real time.

Railway reservations systems are one example where you get immediate booking as soon as you press the button ‘confirm’ and thus it is an online system that is also real time.

    In brief:

    Difference Between Real Time System and Online System

  • Online activity may be real time sometimes but there are online systems that are not real time
  • Real time systems are those where the user gets immediate response to his reaction and there is no time delay
  • If you are typing something and it appears on the screen of another person online after a lag of few micro seconds, it is online but not real time