You can use this system as it is backward compatible as most systems today are.
Compatibility from Linksys' website...
802.11a
802.11g
802.11n
802.11ac
802.11b
Each node is the same. It has 2 ethernet ports on the back. If you use a wired setup such as in an office, then you can use these ports one input and one output. If you are using as a wifi connected setup only, I have found that only the 1st (connected) node works for plugging other things into it.