Java is general purpose Object Oriented Programming Language developed by James Gosling and Patric Naugton, at Sun Micro System. OAK (which is a tree name) is java original name. In the year 1995, OAK was revised and developed software called JAVA (which is a coffee seed name).


JAVA released to the market in three categories that are J2SE (JAVA 2 Standard Edition), J2EE (JAVA 2 Enterprise Edition) and J2ME (JAVA 2 Micro/Mobile Edition).

J2SE is used for developing standalone application/programs development.

J2EE is used for developing client server applications/programs development.

J2ME is used for developing Mobile Application/programs development.

Java source code file (a file with extension .java) is compiled in to byte code format (.class) that byte code runs on any operating system. So java has slogan WORA (Write Once Run Anywhere).

Fallowing are java features:

Java is Platform independent:
Java programs run in JRE (Java Runtime Environment) provided by Java virtual machine so java program is not accessible to operating system directly. This makes Java programs platform independent.

Java is Object-orientated programming language:
Except the primitive data types, it fallows all the principles of Object Oriented Programming Language.

Java is Strongly-typed programming language:
Java is strongly typed, means variables must be declared to contain a specific type of data.

Java is Interpreted and compiled language: Java source code is transferred into the byte code format, which does not depend on any particular platform. These byte code instructions will be executed by the JVM (Java Virtual machine).

Java support Automatic memory management:
Java manages the memory allocation and de-allocation for creating new objects. Garbage collector automatically deletes objects to which no active thread/process is executing. JVM call garbage collector when system memory get full or not enough to run that application.

Secure: java application run inside special environment created by JVM (Java Runtime Environment) That is JRE. So no any process directly access application code or interfere in application.
Simple: Java is easy to learn after learning C++ because java concepts and syntax are similar to C++. Java remove complex Concept of C and C++ like operator overloading, Pointer etc.

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