Java is Everywhere. We are all using java without knowing it existence actually like in browsers, in mobile phones and in electric devices etc...what not. spanned across different devices.
If you want to know which version of java is currently using in your browser, you don't have an option to go to the command prompt and type the command (java -version) to know the version of java installed in your browser because the versions of java installed in browsers varies from one browser to another.
You are just a step ahead of knowing which version of java is installed in your browse with a simple single click of your mouse button.
Just click and know :
How To Know :
In Browser :
After clicking the above link, you will get a web page with an applet running to show existence of java and version of it.
If you are having java in your browser you will get the screen like this
In System :
Go to Comand Prompt ( Windows + R and type cmd in the run window)
type java -version and press enter
You will get to know which version of java is installed in your system.