What is “Real-Time”?
Posted By On May 21, 2010 @ 9:36 AM In Computer Terms | Comments Disabled
I have heard about “real-time”; what is it?
Well, I know my watch says 12:37 pm, but it may not be the real time.
In case that’s not what you meant (and somehow I think it isn’t), let’s talk real time on the Web.
Real time means what is occurring now. It is the actual time an event occurs. Live streaming video is in real time. Watching content on a web cam is in real time. When you watch an NBA Basketball Playoff game, you are watching it in real time (which can make you crazy if things aren’t going well and then maybe you should opt for the non-real time highlights on ESPN).
Real time operating systems (RTOS) are those that respond to input immediately. They update information at the same rate they receive information. They must operate reliably according to specific time constraints. RealTime Linux (RTLinux) is an example of a real time operating system.
Real time can also be an application in which information is received and immediately responded to without any time delay. Google now uses real time search. This means that Google search will update as things happen around the world; news articles and Web pages now stream in on the actual pages returned when you type in a search. If you type in something and Google has given you an option for “News Results”, click on the main heading for the heck of it. You will see that articles have the time whatever result was reported to Google listed on them, or how long ago the news was reported to Google. You can get live updates from people on Twitter on Google. Right after something is published on the web, you can find it on Google. That’s real time.
There are two main kinds of real time: hard and soft. Hard real time does not forgive even a few seconds; for instance, you car brakes are an example of hard real time. If someone suddenly stops in front of you (and you are – ahem – following a little too closely), you don’t to slam on your brakes and have your car stop a few minutes later.
If you are going to fly to your in-laws for vacation (vacation?) your travel schedule is being updated in soft real time. Everything is updated in real time, but it isn’t going to be a huge problem if the schedule is a few seconds off, not like a hard real time failure.
You know, I was just thinking that something I would really like in hard real time is my bank information. I do receive text alerts when I drop below my normal balance, but it would be really nice to know what my actual balance – my real balance – is at the time I am checking on it – the real time. I mean, this really should not be a soft real time occurrence, because if I need to know how much money I have in my account right now – in real time – then I should be able to. And if soft real time means that you can allow a few seconds (or even minutes) for a delay, then what kind of real time is my bank operating on? Maybe really gentle real time.
So that’s what real time means. And I hope the fact that you haven’t read this in real time hasn’t upset any part of your day in any real way.
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