Java Terminologies : Introduction

• There are some basic Java Terminologies that are used frequently. These terminologies include Java Virtual Machine(JVM), Java Run-time Environment(JRE) and Java Development Kit(JDK). So let’s discuss them in brief.

1. Java Virtual Machine (JVM)

   • Heart of Java programming language.
   • JVM is a program for a particular hardware and software platform that run Java technology applications.
   • JVM is an abstract machine architecture specified by the JVM specification.
   • JVM is responsible for converting byte-codes to machine specific code.
   • In other words JVM is a platform dependent execution environment that converts Java bytecodes into machine language and executes it.



2. Java Runtime Environment (JRE)

   • JRE is a run-time environment which implements JVM and provides all class libraries and other facilities necessary to execute Java programs.
   • Consists of JVM, core classes and supporting files.
   • JRE doesn’t contain any development tools like compiler, debugger etc.
   • Platform specific.



3. Java Development Kit (JDK)

   • The tools necessary to compile , document and package Java programs (Javac, Javadoc and jar) is included by JDK.
   • JDK includes a complete JRE.
   • Core component of Java , provides all the tools, executable and binaries required to compile, debug and execute Java programs.
   • JDK = JRE + Java compiler + debugger + core classes.
   • It is also a platform specific software.

Note : Apart from these three,  other common terminologies that are used in java programming languages can be checked here.