oracle vm

Hello
When you create a vm like oracle box and then import an os to it like Win 8 or Ubuntu, if you decide to remove these, can you simply remove the vm and all is gone, or, are there remnants.
I ask because I am thinking of creating Win 8 in Oracle's vm but reflect back to my last vm experience. I usd Oracle's vm with used Ubuntu. After a while I decided to remove the vm thinking Ubuntu would be gone as it was part of it.
I found Ubuntu deeply entrenched within my host pc.

This is why I ask if I made an error before or should the guest remain even after the vm is removed?
Thank you
Peter

It has been awhile and I only did it once because of the residual files.

I found Ubuntu in several places on my pc which prompted me to use Acronis to become stable again. I also found vm in different places.
I did not see any selection to remove files so apparently I did it wrong.
How do you remove the VM the proper way so you have a choice to remove everything?
I thought you could remove the VM or the guest but I did not know the proper way to do it so nothing was left over.
I did not want to randomly delete folders in case one was shared or a file was necesary.
I would like to use the Oracle VM with Win 8 as long as I could remove it all when I wanted.
If I knew how to remove a guest I could add them as I needed, to investigate.

Long short = how to remove guest and vm?

So to remove the guest, right click the one you want, click remove and follow up with remove all the files.
If you remove all files will the guest and Oracle vm be removed or just the guest?
Or when you want to remove the Oracle vm, do you click on settings?

I guess what I have to understand is what the vm is. I thought it was only Oracle and that you imorted guests into it.

I amend that comment.
All are vms and to completley rid the pc of the Linux Mint for example you right click, then click to remove all. That takes care of that particular Linux Mint vm but the Oracle remains. Then you remove each the same way. If you wish to remove the Oracle machime.... this is where I do not understand.

For example, if you had Win 7 , Oracle, Mint.

Is Mint the guest, Win 7 the host and Oracle the software but neither host nor guest.?