is it true that the java -version command returns the java version for the java that I use to browse the web, but the java version that I use in netbeans / eclipse can be a totally different version?
In fact can the version of java i use in netbeans and eclipse be different?
Or is it that a system only has 1 version of java that works throughout all applications?
The version of Java that is used in the browser is defined in the control panel. This defaults to the version that is returned by java -version. IE uses a JRE.
When NetBeans is installed, it asks which version of Java to use, so this is not necessarily the same as IE, alkthough it may default to the same version JDK.
NetBeans and Eclipse can be configured to use a different version of the JDK than the standard one, so you can’t guarantee that IE and NetBeans/Eclipse use the same version of Java.
On Windows, you can have as many versions of Java on a machine as you want.