Explain the basic concepts of object-oriented programming. Why is java known as platform-natural language? Explain the concept of virtual machine in java programming language along with block diagram.

 Basic concepts of object-oriented programming:

1. Abstraction: Abstraction allows us to represent complex real-world entities as simple and manageable objects in our program. It focuses on essential features while hiding irrelevant details from the users.
2. Encapsulation: Encapsulation is the process of binding data members and methods within a class, preventing the direct access of data from outside the class. This helps to maintain the integrity of the class.
3. Inheritance: Inheritance is a mechanism by which a new class is derived from an existing class, inheriting the properties and behavior of the parent class. This promotes code reusability and enhances the structure of the code.
4. Polymorphism: Polymorphism refers to the ability of objects of different classes to be used interchangeably. This is achieved through method overloading and method overriding.

Java is known as a platform-natural language because it can run on any platform that has a Java Virtual Machine (JVM) installed, regardless of the underlying operating system and hardware architecture. Java source code is compiled into bytecode that can be executed by a JVM, which translates the bytecode into machine code that can be understood by the specific hardware.

A virtual machine is an abstract computing machine that simulates the behavior of a physical machine. In the context of Java programming language, the virtual machine is known as the Java Virtual Machine (JVM). The JVM provides the runtime environment for Java programs and is responsible for executing Java bytecode.

When a Java program is compiled, it is translated into bytecode, which is a platform-independent code that can be executed by any JVM, regardless of the underlying operating system and hardware architecture. The JVM interprets the bytecode and translates it into machine code that can be executed by the specific hardware.

The following block diagram illustrates the concept of the JVM in Java programming language:

In this diagram, the Java application is compiled by the Java compiler, which produces bytecode that is platform-independent. The bytecode is executed by the JVM, which translates it into machine code that can be executed by the operating system and hardware. The JVM provides a runtime environment for the Java program and is responsible for managing memory, garbage collection, security, and other aspects of the Java program.

The use of a virtual machine in Java programming language makes Java a platform-independent language. Java programs can run on any platform that has a JVM installed, without the need for recompilation. This feature has made Java a popular choice for developing cross-platform applications.