networksetup
is the CLI interface for network settings panel in System Preferences. From the man page
:
The networksetup command is used to configure network settings
typically configured in the System Preferences application.
ifconfig
is the utility to set up a network interface. From the man page
The ifconfig utility is used to assign an address to a network
interface and/or configure network interface parameters.
What you are seeing is two different methods with different nomenclature for the same thing.
networksetup
is specific to macOS where ifconfig
is more generic and part of the BSD core
As to your question...
Can a single network interface have multiple network services?
Yes. For instance, you can have an alias for that interface. Using actual System Prefs (because it's visually easier), I created a new service called "Ask Different Demo" to my existing interface "Ethernet"
