Your question is difficult to understand. Yes, you can install Ubuntu in virtualbox. That runs as a program in your main operating system. That is not the same as dual-boot, where you have two operating system side by side but only run one at a time. That's also perfectly possible with Ubuntu, but that's something entirely different and you don't need VirtualBox for that.

I hope it answered your question. If you edit your question to be easier to understand, I can probably provide a better answer.