I'm brand new to the concept of virtualization and VMs and have downloaded VirtualBox and created my first VM (an Ubuntu box).
I understand that a "virtual appliance" is very similar to a VM, however it comes with a pre-configured software stack and may even include multiple virtual machines. If this first assumption is not correct, please correct me!
My main question is this: in VirtualBox land, what is the difference between creating a virtual machine and a virtual appliance? Are they different file types? If I had two or three VMs, how would I go about turning them or packaging them into an appliance?