What is Java Virtual Machine?

Java Virtual Machine (JVM) is a set of computer software programs and data structures which implements a particular virtual machine model. This model agrees to a form of computer intermediary language, normally referred to as Java bytecode, which conceptually signifies the instruction set of a stack-oriented, capability architecture. This code is primarily often generated by Java language compilers, even though the JVM can as well be targeted by compilers of other languages. JVMs using the "Java" trademark can be developed by other companies as extensive as they adhere to the JVM requirement published by Sun and related to contractual obligations.

The JVM is a crucial part of the Java Platform. Since the JVMs are accessible for many hardware and software platforms, Java can be equally middleware and a platform has its own right — therefore the expression "write once, run anywhere." The use of the alike bytecode for every platforms allows Java to be described as "compile once, run anywhere", as opposed to "write once, compile anywhere", which denotes cross-platform compiled languages. The JVM as well enables such exclusive features as Automated Exception Handling which gives 'root-cause' debugging information for all software error (exception) independent of the source code.