Introduction to Java
Java is a high-level programming language originally developed by Sun Microsystems and released in 1995. Oracle Corporation took acquisition of Sun Microsystems in 2009-10. Java runs on a variety of platforms, such as Windows, Mac OS, and the various versions of UNIX.
Fetures of Java :
Simple.
Object-Oriented.
Platform independent.
Secured.
Robust.
Architecture neutral.
Portable.
Dynamic.
Interpreted.
High Performance.
Multithreaded.
Distributed.
What is JVM ?
Java Virtual Machine (JVM) is a virtual Machine that provides runtime environment to execute java byte code. The JVM doesn't understand Java typo, that's why you compile your *.java files to obtain *.class files that contain the bytecodes understandable by the JVM.
What is JRE ?
The Java Runtime Environment (JRE) provides the libraries, the Java Virtual Machine, and other components to run applets and applications written in the Java programming language. JRE does not contain tools and utilities such as compilers or debuggers for developing applets and applications.
What is JDK ?
The JDK also called Java Development Kit is a superset of the JRE, and contains everything that is in the JRE, plus tools such as the compilers and debuggers necessary for developing applets and applications.
Applications of Java :
Developing Desktop Applications.
Web Applications like Linkedin.com, Snapdeal.com etc.
Enterprise Applications such as banking applications.
Mobile Operating System like Android.
Embedded Systems.
Robotics and games etc.