* Root Panel : It is the topmost panel where all other widgets are attached to it.
* Flow Panel : It is the simplest panel which provides a basic HTML layout.
* HTML Panel : It is enclosed with specified HTML contents.
* Form Panel : It specifies that any widget declared in this would be wrapped in HTML form element.
* Scroll Panel : It puts all the content in the scrollable area.
* Grid : It helps to create an HTML table.
* Flex Table : It extends HTML table like a GRID, but here we can create a table on demand.
