OS simulator thing?

[Kawaii Penguin]

What's the program where you can run an OS within your computer , similar to a simulation? I think it runs with Java.

 

[Corwin65]

A Virtual Box?

 

[rickypratama]

It's called virtualization software. The softwares I know for pc os virtualizations are VMware and virtual box.
For android/java emulator, the softwares are genymotion and nox