What is the difference between JDK & JVM ?

Answer 1

JDK stands for Java development kit it is a complete package for developing, debugging and testing java code, it consist of following tools:
javac (java compiler)
jar (java archiving tool)
jdb (java debugging tool)
jre (java runtime environment)

Now coming to JVM (java virtual machine) it is a part of JRE when source code in java is compiled by compiler it convert into bytecode with .class extension this compiled code is not suitable for computer yet but it is designed to run on JVM which then interpret it into machine language suitable for computer.

JVM is main component of java because due to this only java is portable and architecture independent but jvm is system dependent, any machine that has Jvm installed can run java bytecode(.class)

Answer 2

JVM is the engine, the box where Java applications runs; JDK is a library of tool for developer to create Java applications.

Answer 3

JDK distibution package contains JRE (Java Runtime Environment) that contains JVM, basis Java libraries and a launcher. To run Java applications doesn't need JDK, but only JRE.