The selected window is the one that you edit in. When a window is selected, the buffer in the window becomes the current buffer, and the cursor will appear in it.
(Info-goto-node "(elisp)Selecting Windows").
val get : unit -> Ecaml.Window.t (describe-function 'selected-window)
val set : ?move_to_front_of_buffer_list:bool -> Ecaml.Window.t -> unit(describe-function 'select-window)
val switch_to_buffer : Ecaml__.Import.Buffer.t -> unit(describe-function 'switch-to-buffer)
val switch_to_buffer_other_window : Ecaml__.Import.Buffer.t -> unit(describe-function 'switch-to-buffer-other-window)
val split_horizontally_exn : unit -> unit(describe-function 'split-window-horizontally)
val split_sensibly_exn : unit -> unit(describe-function 'split-window-sensibly)
val split_vertically_exn : unit -> unit(describe-function 'split-window-vertically)
val find_file : string -> unit(describe-function 'find-file)
val find_file_other_window : string -> unit(describe-function 'find-file-other-window)
val view_file : string -> unit(describe-function 'view-file)
val save_selected_window : (unit -> 'a ) -> 'a (describe-function 'save-selected-window)
val set_temporarily : Ecaml.Window.t -> f:(unit -> 'a ) -> 'a (describe-function 'with-selected-window). Avoid using set_temporarily, which can have visual artifacts that annoy the user, like flicker of the mode line or cursor.
val save_window_excursion : (unit -> 'a ) -> 'a (describe-function 'save-window-excursion)
val quit : unit -> unit(describe-function 'quit-window)
val other_window : int -> unit(describe-function 'other-window)