Also, to help visualize things a little better
- Server Only: GameMode
- Server & Clients: GameState, PlayerState, Pawn
- Server & Owning Client: PlayerController
- Owning Client Only: HUD, Widgets
Highly recommend the Networking Compendium eXi put together http://cedric.bnslv.de/Downloads/UE4_Network_Compendium_by_Cedric_eXi_Neukirchen.pdf