In Java Button, Checkbox, Lists, Scrollbars, Text Fields, and Text Area etc positioned by the default layout manager.
Using algorithm layout manager automatically arranges the controls within a window.
In Windows environment, we can control layout manually.
But we do not do it manual because of following two reasons:
1. It is very tedious to manually lay out a large number of components.
2. Sometimes the width and height information is not available when you need to arrange some control, because the native toolkit components have not been realized. This is a chicken-and-egg situation.
Java uses layout managers to lay out components in a consistent manner across all windowing platforms.