Tkinter provides a powerful concept typically not found in Windows GUI toolkits, and that is geometry management. Geometry management is the technique used to lay out child widgets in their parent (for example, controls in a dialog box). Most traditional Windows environments force you to specify the absolute position of each control. Although this is specified in dialog units rather than pixels and controls can be moved once created, Tkinter provides a far more powerful and flexible model.
Tkinter widgets provide three methods for geometry management,
is the simplest mechanism and similar to
what most Windows users are used to; each widget has its position
explicitly specified, either in absolute or relative coordinates. The
mechanism, as you may expect,
automatically aligns the widgets in a grid pattern, while the
method is the most powerful and the most
commonly used. When widgets are packed, they are automatically
positioned based on the size of the parent and the other widgets
already placed. All of these techniques allow customization of the
layout process, such as the padding between widgets.
These geometry-management capabilities allow you to define user interfaces that aren’t tied to particular screen resolutions and can automatically resize and layout controls as the window size changes, capabilities that most experienced Windows user-interface programmers will know are otherwise difficult to achieve. ...