Step: 1 Know Java Platform
Reference
http://java.sun.com/javase/technologies/index.jsp to the image
shown below (updated

Basically Java SE encompasses three phases ( phases means,
logical layers with developing objects having precise entropy or
degree of freedoms that won't disturb the conformation of Java
Platform). The Java Developing Kit delivers the packages to install
API and a run time environment.
All the above can be framed as an image shown below.
