Introduction to Java Platform

Before you can develop an application written in the Java programming language, you will need the Java Platform Standard Edition (Java SE) development kit. It has the necessary Java Virtual Machine ¹ (JVM), core Application Programming Interfaces (API)s, and the compiler you'll need for most and perhaps all of your development.
If you are used to working in an Integrated Development Environment (IDE) or want to learn, you can download Java SE with the NetBeans IDE. 

Some important tools in Java platform are:-

• Java SE: This kit is necessary for developing all applications, except those designed for consumer devices (See the Micro Edition). Java SE comes bundled with the compiler, a runtime environment, and core API.
• Java Platform Enterprise Edition (Java EE): This packages includes an application server, web server, J2EE APIs, support for Enterprise JavaBeans, Java Servlets API, and JavaServer Pages (JSP) technology. Use J2EE with the Java SE.
• Java Platform Micro Edition (Java ME): If you are interested in developing programs for Palm Pilots, screen phones, and other consumer devices, this kit provides tools for compiling, deployment and device configuration, and APIs that are specialized for each type of device.
• JavaFX Script Technology is a highly productive scripting language that enables content developers to create rich media and content for deployment on Java environments.