Animation is defined as a rapid display of text or images. These images or text have to be created in a specific pattern. When they are dispayed rapidly it causes an appearance of movement.
In JTree data are stored in Hierarchical way.JTree displays the data vertically.A tree has a root node and branches nodes.import javax.swing.tree.*; package is used to create the tree (all nodes).
JDesktopPane and JInternalFrame are two classes which is used to create MDI(multiple document interface) in Swing.JDesktopPane works as a container for other windows and JInternal Frame is same as JFrame means we can add components in the internal frame in the same way as JFrame.
The ComboBox component,is a combination of textfield and drop down list of items.User can make selection by clicking at an item from the list or by typing into the box.It can be created by instantiating the JComboBox class.
A rigid filler is similar to pair of struts(A strut is a fixed width invisible component(give certain amount of space in the components(any component like button textfields))).It is an invisible(not shown) component with a specific width and height.