Java specification

Java JDK or JRE or both are specifications? Can anyone quote some开发者_JAVA技巧 relevant implementations?

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The JDK (Java Developer Kit) and JRE (Java Runtime Environment) are (in part) both implementations of the Java Language Specification and The Java Virtual Machine Specification. JRE and JDK may or may not refer to the Sun JRE and Sun JDK depending on context. You can see this list of JVMs (Java Virtual Machines). There are also third-party java compilers, the most popular being ecj and gcj.

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JDK means Java Development Kit. it provides you a tool or the files , key words , tokens or java extensions which helps to make a java program, its provide java tool to write java program or another Hand JRE that means Java Run-Time Environment which helps your OS to understand that what is going to be Run , in short if we says that JRE is same as OS, that provide an environment to execute java program .

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JDK is Java Development Kit, a toolset used to write Java programs. JRE is Java Runtime Environment, the virtual machine that executes Java bytecode. Naturally the Sun implementations of both are widely used

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JRE definition from java.com:

The Java Runtime Environment (JRE) is what you get when you download Java software. The JRE consists of the Java Virtual Machine (JVM), Java platform core classes, and supporting Java platform libraries. The JRE is the runtime portion of Java software, which is all you need to run it in your Web browser.

And here is an article from wikipedia about what is JDK