What is the purpose of Java JDK to Eclipse?
eclipse, java
Solution
There are a number of tools that come with the JDK that don't come with the JRE - JConsole (http://java.sun.com/developer/technicalArticles/J2SE/jconsole.html) springs to mind. This for example can help you understand & monitor the memory usage of your application and so on. Either way if you head into unfamiliar territory, I highly recommend you follow the Eclipse suggestion and use the JDK!
Problem
I've just installed Eclipse, after i installed the java JDK. The Getting Started guide (in Eclipse) says i should reference my JDK installation in Window>Preferences>Java>Installed JREs, but that a JRE would also work. Select the Java > Installed JREs preference page to display the installed Java Runtime Environments. Confirm that a JRE has been detected. By default, the JRE used to run the workbench will be used to build and run Java programs. It should appear with a checkmark in the list of installed JREs. We recommend that you use a Java SDK instead of a JRE. An SDK is designed for development and contains the source code for the Java library, easing debugging. There was already a JRE set up there (not a JDK), so i did nothing and tried to compile a Hello World (just to see what would happen). To my surprise, it compiled! I searched a little bit and it looks like this works because Eclipse has a built-in Java Compiler. I tried debugging using the same eclipse set up, and it was also successful. So, what is the difference between setting a JDK and JRE there? Why is it important to download the JDK, since in my default configuration Eclipse doesn't seem to use it?