what is meant by java virtual machine(JVM)?

Answer 1

It's the platform that allows programs and applets written in the Java programming language to run on your computer.

Answer 2

Acronym for Java Virtual Machine. An abstract computing machine, or virtual machine, JVM is a platform-independent execution environment that converts Java bytecode into machine language and executes it. Most programming languages compile source code directly into machine code that is designed to run on a specific microprocessor architecture or operating system, such as Windows or UNIX. A JVM -- a machine within a machine -- mimics a real Java processor, enabling Java bytecode to be executed as actions or operating system calls on any processor regardless of the operating system. For example, establishing a socket connection from a workstation to a remote machine involves an operating system call. Since different operating systems handle sockets in different ways, the JVM translates the programming code so that the two machines that may be on different platforms are able to connect.

JVMs are not the only virtual machines being used today.

Answer 3

It's a virtual machine that mimics a computer. It makes a Java program see your computer as a Java machine. Java virtual machine creates an "imaginary" Java machine that understands the Java language.

It is written in software and it sits on top of your real hardware and emulates a machine as though it was a computer able to understand Java bitcode as its instruction set. (This is the reason for it being called a Java "Virtual" Machine.)

This is what allows Java to be run on any platform that can run the Java Virtual Machine. The Java program is written for the Java Virtual Machine and not the actual hardware.

Answer 4

Java is a program language that can be used on any type of computer, Windows, Mac, Unix, Linux, etc. It works by loading a program called a "Virtual Machine" on your computer. The "Virtual Machine" is unique to each type of computer (one for Windows, one for Mac, etc.). The "Virtual Machine" is like a computer that only exist in your computer's virtual memory. That fake computer is what runs the Java program on your computer. When you are done running the program, the "Virtual Machine" is removed from memory.