What is commonly known as a window is called a toplevel widget
in Tk and HTK. They are created with a function
but (of course) they need not be packed, they just appear. Toplevels are containers (instances of Container), so you can just pack other widgets into them. They are closed by destroying them (see Sect. 2.3).
The familiar properties expected from a window are all in the class Window from module Window.htmlWindow. Its size can be configured either by classes HasGeometry or HasPosition and HasSize, and its title by the class HasText. The screen configuration sets the screen the window appears on (the display in X windows speak). Toplevels can have a menu attached which is the system menu for this window.