Core Java

Java is a general-purpose programming language. Much of the syntax is derrived from C & C++ but Java has fewer low-level dependencies than those other languages. For example, in C++ it's not uncommon for the programmer to have to manage memory usage. Java handles this automatically.

Java is an object-oriented programming language. Java programs are compiled to bytecode which can run on any Java virtual machine, JVM. Java aims to allow the programmer to write once, run anywhere. In theory you should be able to run the same Java program on a linux machine as a Windows machine. This is mostly true but some implementation details hamper this goal.

Java was developed in the early 1990's at Sun Microsystems by James Gosling. Sun has since been acquired by Oracle Corporation so they now maintain Java.

Java is one of the most popular programming languages in use today.

Java Versions

Major release versions of Java, along with their release dates:

JDK 1.0 (January 21, 1996)
JDK 1.1 (February 19, 1997)
J2SE 1.2 (December 8, 1998)
J2SE 1.3 (May 8, 2000)
J2SE 1.4 (February 6, 2002)
J2SE 5.0 (September 30, 2004)
Java SE 6 (December 11, 2006)
Java SE 7 (July 28, 2011)
Java SE 8 (March 18, 2014)

Core Java vs. Java EE (Enterprise Edition)

Core Java refers to Java SE. It includes the Java Language, the Java Virtual Machine (JVM) and Java Development Kit (JDK). The JDK contains the compiler, some tools and a library. The library is called the Java API (Application Programming Interface). It consists of classes developed by Oracle/Sun that go with Java. Core Java is used for general purpose programming.

Enterprise Java refers to Java applications written to meet the needs of enterprises. An enterprise is an organization rather than an individual user. Such organizations include businesses, schools, interest-based user groups, clubs, charities, or governments. Java EE consists of a set of APIs (EJB, JMS, JPA, JTA, JSF etc.) and the application servers (Glassfish, Tomcat, JBoss/WildFly etc.) which implement these APIs (or a part of them).