JDK install

2) Java has a separate installation for development because it is a compiled language. You need a compiler and some supporting files and classes (that is, the JDK) to develop software. But you don’t need that to run Java programs, you just need the Java Runtime Environment.

If you want to develop Java applications, download the Java Development Kit, or JDK. The JDK includes the JRE, so you do not have to download both separately . If you need the JRE on a server and do not want the ability to run RIAs, download the Java SE Server JRE.

1 Answer. You do not need to install JRE then, as JDK usually consists of both development & run-time environments in it. If you install JDK then JRE will already be packaged in it and installed automatically along with JDK.