Can I create games that has multi-windows like apps like Chrome, Word, ... using Godot?
In Godot 4.0, there will be support for multiple windows in Godot games: Godot Dev Blog post. However, in Godot 3, there is currently no way to make a multi-window game, at least not that I know of.
Perhaps as a local networked application implementing a client-server approach?
You can use PopUpWindow, but it's just a "window" inside your game window. Still may be useful, if you need complex UI