Windows are different portions visible within the same UI “window”, whereas frames are actually separate UI “windows.”

Split Window

• C-x 2: Split the current window into two windows, one above the other (split-winbdow-vertically).
• C-x 3: Split the current window into two windows, side by side (split-windows-horizontally)
• C-x o: Go into the next window.
• C-x 0: Delete the current window.
• C-x 1: Close all the windows, except for the current one.
• C-x }: Shrink window (C-u C-x } shrinks 4 times, C-u C-u C-x } 16 times, etc.)
• C-x {: Increase window size

Frame

• C-x 5 2 : Create new frame.
• C-x 5 o: Go into the other frame.
• C-x 5 0: Delete the current frame.
• C-x 5 1: Delete all the frames, except for the current one/

Menus and Toolbars

To permanently hide the menubar and the toolbar, add the following to your init file:

(menu-bar-mode nil)
(tool-bar-mode nil)