I'm trying to understand the difference between basic and dynamic disks. From what I've read I think I understand basic disks well enough since this is what I've been using.

They are also smart enough to store the ENTIRE disk map in that table, so if you have multiple dynamic disks in a system and one of them eats its volume table, it can be recreated on the disk by ...

To convert from fixed to dynamic, use VBoxManage.exe clonemedium disk "source.vdi" "destination.vdi" –variant Standard, whereas, to convert from dynamic to fixed, use VBoxManage.exe clonemedium ...