Is java a platform

On internet,i have read at one website the question :
What is difference between java platform and other software platforms ?

Is java a platform?
I think platform means operating systems like Windows,Macintosh etc.

Well, what other people mean with "platform" is obviously not "operating system", because Java is not an operating system.

Sorry young if my question is not clear.
I know java is not an operating system and in general as according to me,platform means operating system.
So why is java called as platform.

"Platform" does not mean "operating system".

"platform" does not necessarily mean operating system, but it CAN mean that. see here for one definition. it can refer to hardware OR software, and probably many other ways.

So, back to your original question - Is java a platform - it depends on which definition of platform you are using.

Java : see Platform

Platform : see Java

Platform is whatever you mean when you say it. When Sun said it, they meant a sandbox that is all our code needs to know about. So you can go full "Dead Parrot Sketch" and say "No it isn't!" if you want.

(Sorry for that culturally narrow joke. I don't have access to YouTube here so can't give a link. If you don't know it, look for Dead Parrot. It's worth the trip.)