Introduction of Java

 Java is high level, object oriented programming language, Java language is developed by James Gosling and his team at Sun Microsystems.

Features of java

• Object Oriented programming(OOP)
• Platform Independence
• Robust and Secure
• Multi threading and concurrency
• Rich API and Standard Libraries
• Maintainability and Scalability

Main Components : 
three main components that work together to develop and execute programs : the JDK, JRE, JVM.

JDK (Java Development Kit):-

JDK provides tools and libraries needed to build java based applications and applets it work together with JVM (java virtual machine) JRE(java runtime environment) as part of core java setup

If you want to run java programs installing JRE is enough but you want to develop java applications you 'll need the JDK, which includes JRE and additional development tools.

                JDK= JRE+ development tools.

JRE (Java Runtime Environment)

It provides minimum requirements to execute java application, following elements create functional environment for java JVM.

• java class libraries
• class loader
• supporting files.

            JRE= JVM + class libraries

JVM (Java Virtual Machine)

It provides a runtime environment for executing java byte code, core component that enables java's main feature: Write Once, Run Anywhere.

•     Loading: Class loader to load .class file into memory.
•     Verification: The Bytecode verifier.
•     Execution: The execution engine converts byte code into native machine code using a interpreter (line by line) or Just-in-time (JIT) compiler.
•     Memory management: It automatically manages memory allocation and performs garbage collection from unused objects in memory.