Java originated from a language called Oak that was developed by Sun Microsystems in the early 1990s. When Oak failed, Sun changed the name to Java and modified it to work with web browsers. Java is an object-oriented language similar to C++ but was designed to eliminate common programming errors. Java source code is compiled into bytecode that can be run by a Java interpreter on any platform. The Core Java course covers topics like layout managers, event handling, graphics, networking, databases, collections, and project training.