I have been experimenting with Linux recently and I've come across a dev argument in some commands when dealing with networks. E.g.:

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  ip link set dev wlan0 up/down
  
  

  
  


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  ip link set dev wlan0 address XXX
  
  

  
  


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  nmcli dev show wlan0
  
  

  
  

The ip link commands seem to work without the dev argument as well. For nmcli I think it lets the system know that I'm talking about a device, and I guess that it has a similar purpose for ip link. I'm slightly confused why it's there if it works without it though.

Did ip used to need it, but now it's "smarter" or is it something different?