Java API(Web Resource) -
An API stands for a "Java Application Programming Interface". It is like a super dictionary of the Java language, that one uses to look something up in. It has an index or collection of all Java packages, classes and interfaces, with all of their methods, fields and constructors, and how to use them. When one programs, there are many classes that are commonly used, and therefore pre created, so that the programmer doesn't need to create them from scratch. Let's look, for example, at a computer window frame. If the programmer had to create one from scratch, he would have to write hundreds of lines of code, to create the scroll down menu, the exit box, etc. Since a window frame is very popular, Sun has written the code for one, and all that you have to do is import the package that contains the window frame, and instantiate one with a new statement.