I know how to create "interfaces" and assign them an IP range.
I see how to create a "bridge device" which makes the link between several physical ports and allows to create tagged or untagged vlans between these ports.
What is the link between a Vlan (ID1 2 3 4...) which has no IP range and an "Interface" that has been defined in other section with its IP range?
VLANs are just a method to have several independent networks running separately on the same wire.
So, eth0 refers to both the physical ethernet interface, and the untagged packets on that interface. Then, eth0.1 are the packets on eth0 tagged on VLAN 1.
Those are the physical interfaces, now you can create network interfaces by assigning IP addresses to them.