What is Java Development Kit (JDK)?

Java Development Kit (JDK) is a collection of tool which enables developers to create, test and execute java programs. JDK contains development tools (ex: javac, appletviewer etc...) and Java Runtime Environment (JRE)

Q: What is the difference between JDK and JRE?
A: JDK allows developers to create, test and execute programs whereas JRE only allows users to execute programs.