By using a calculator we can calculate arithmetic operations(mathmetical computations) on numbers .Arithmetic operations means addition, subtraction,multiplication, divison etc.
JButton is a Swing Component which defined in package javax.swing.*;This program helps to change the Label(Caption) of the Button.The label of the Button “New” is changed into “Save” .
A tool bar is a button bar that gives quick access to the most commonly used commands in a program.Tool bar are made up of buttons,there is no restriction on the components that you can add to a tool bar.
Borders are basically a margin around the edges of a Swing component. Borders are useful for providing titles and empty space around components.The setBorder() is used to put a border around a component.