MBR code can be anything. As pointed out by Martin is his answer and as suggested in your other question regarding the topic the MBR contains a section that has the bootstrap code. As it is an arbitrary section it can contain any form of code. It could be empty, it could be code that displays a funny message or a whole bootloader.
Consider GRUB which is a common bootloader. Just for some graphic representation from the GRUB Wiki article take this Image by ScotXW:
As you can see it's a multi stage process but the initial
boot.img would be specific to GRUB. The subtitle of that image states (which is also visible in the image):
GNU GRUB on a MBR-partitioned hard drive; stage 1 (boot.img) can alternatively be written into one of the VBRs.
So the code in that particular memory location is generic enough/smart enough to not be dependent to be in the MBR bootstrap location but instead can also be in a VBR. Yet it would still be very different from what e.g. the Windows boot loader looks like. With modern security and everything it's becoming more common to have those chain loaders.
- Maybe. If you look at this it would suggest that it's just a name for the first sector of a volume. As such each volume would have a VBR after creation.