What is the difference between the JRE and JVM? [duplicate]

Answer 1

First of all JDK contains JRE+development tools, JRE contains JVM+class libraries, where JVM contains (class loader & byte code verifier) and the Execution engine (interpreter & JIT).

The compiler will convert the source code into intermediate byte codes. Where this byte codes is given to JVM for execution, the class loader in the JVM will load the byte codes and does linking with class libraries provided by the JRE.

Then the code will be given to the execution engine in the JVM which interprets the unrepeated code and compiles the repeated code (for example loops) finally converting into machine code (object code). Then it will give the machine code to the microprocessor for execution.

Answer 2

JRE and JVM is part of JDK. jdk=jre(contains JVM)+Development tools.

JVM is specification and the name of JVM Implementaion is Hotspot or others, Implemented by different organizations.

Answer 3

The JRE is the environment within which the virtual machine runs.

JRE - JAVA Runtime Environment

JVM - JAVA Virtual Machine

JRE is the container, JVM is the content.

Answer 4

The JRE includes the JVM, which is what actually interprets the byte code and runs your program. To do this the JVM uses libraries and other files provided by the JRE.

I believe you would say that the JRE is like the .NET Framework, while the JVM is like the .NET CLR. There are probably some important differences here I am not aware of though.

Answer 5

The JVM is the process that runs the Java code, and the JRE are all files distributed to form the "environment" in which the JVM runs.

Answer 6

JRE is an environment, in order to execute any Java program locally.

JVM is where it's responsible for converting the Bytecode into machine specific code and makes java program write-once-run-anywhere.