I have read about Virtualbox using which we can run both windows and ubuntu parallely, but it seems that for this we have to make one host and install the other one using Virtualbox in it. (Please correct me if wrong)

I am already using both ubuntu and windows on my pc (dual boot) and I want to run the already existing ones parallely instead of installing one of them again (don't want to install the softwares again). So, is there a way by which I can do this?

Thanks