Question

what r lay out managers

Answer 1

Layout managers are software components used in widget toolkits which have the ability to lay out graphical control elements by their relative positions without using distance units.

Answer 2

Layout managers are software components used in widget toolkits which have the ability to lay out graphical control elements by their relative positions without using distance units. It is often more natural to define component layouts in this manner than to define their position in pixels or common distance units, so a number of popular widget toolkits include this ability by default. Widget toolkits that provide this function can generally be classified into two groups:

Those where the layout behavior is coded in special graphic containers. This is the case in XUL and the .NET Framework widget toolkit (both in Windows Forms and in XAML).Those where the layout behavior is coded in layout managers, that can be applied to any graphic container. This is the case in the Swing widget toolkit that is part of the Java API.