What is Java?

The first question that comes to mind is 'what is Java?'. Java is actually 2 things:
  • Java is a programming language.
  • Java is a platform.
Java is a high level object oriented programming language that allows one to write computer programs/applicagtions.
Java is also a platform as it provides runtime to execute java programs and has its own memory and resource management.

Java Technology Overview

Java is divided into 4 categories:
  • Core Java or Java SE (J2SE)
  • Advance Java or Java EE (or J2EE)
  • Java ME (or J2ME)
  • Java FX
Note: Java FX was first introduced in 2007. Before that Java had only 3 platforms.
Java SE was also called J2SE from java version 2 onwards till Java 6.

Java SE or Java Standard Edition

Java SE (core java) is for developing stand alone applications. It is basic. Provides basic java libraries and concepts like OOPS, exception handling, threading mechanism, collections etc. These things will be used even when you are writing a web-application (J2EE)

Java EE or Java Enterprise Edition

Java EE is for developing web based application (client-server). It includes technologies like Servlets, JSP, EJB, JDBC etc.

Java ME or Java Micro Edition

Java ME is used for micro deveices and embeded development like mobile phone, sensors, micro-controller, TV set-top boxes etc.

Java FX

Java FX is for developing rich UI applications. It is supposed to be a replacement of Java Swing/AWT in long run.