What is the Difference between JDK and JRE?

Answer 1

If you want to develop Java you need JDK. just to run Java applications JRE is enough. as mehdi said JRE is part of JDK

Answer 2

JRE is a part of JDK.

Answer 3

JRE stands for Java Run time Environment and it is a methodology used to provide a virtual environment for all Java source code to run. In this way we provide all required functionality to our program but at the same time keep it encapsulated in a virtual environment so as it could not be a security threat for our system. We restrict our code to run only in the provided virtual environment,where as JDK stands for Java Development Kit. It means all the tools and functionality like Java loader, Java compiler , or Java document generator  available to us using which we can code in java. It is basically meant for developers of jave unlikely JRE which is needed by every device to run Java. JDK also contains JRE in it so as Java developers can test their programs by running it in JRE.

Answer 4

JDK is Java Development Kit while JRE is Java Runtime Environment first is used for development(writing) of programs in Java while the second is used only for running (reading) those programs