I'm a networking newbie and I'm a little bit confused about the difference between the terms:
I've seen network diagrams where a business's network was divided into three main "zones", which seemed like just sub-networks: (1) Intranet (private subnet), (2) Extranet (protected subnet) and (3) an Internet with public-facing web servers (public subnet).
My understanding is that you only create these zones/subnetworks when you have a business need to do so (if you don't need an extranet, don't build one!). But within these zones/subnetworks, you structure the devices & nodes according to the topology that makes the most sense.
First of all, if anything I have said so far is incorrect, please begin by correcting me! And if "zone" is different than "subnetwork", please let me know how and why!
Assuming I am more or less understanding the gist of things, what devices are then used to connect zones/subnets with each other? For instance, how what network devices connect a laptop inside the intranet to an FTP server inside the extranet?
I guess at the root of this question is this: I understand that topologies exist at the network/sub-network levels to provide cabling/connection layouts. But in a situation where you have multiple sub-networks connected to one larger network, what topologies/patterns/devices/best practices, etc. apply to inter-subnet communication? Thanks in advance!