Java standard library or API includes hundreds of classes and methods grouped into several functional packages. Most commonly used packages are
Language Support Package A collection of classes and methods required for implementing basic features of java
Utilities Package: A collection of classes to provide utility functions such as date and time functions.
Input output Package: A collection of classes required for input and output manipulation
Networking Package: A collection of classes for communicating with other computers via internet
AWT package : The abstract window toolkit package contains classes that implements platform independent graphical user interface.
Applet package: This includes a set of classes that allows us to create java applets . Compiling the program