Java, Core Java and Advanced Java are three levels of Java knowledge.

1. Java: This is the basic level, in which you can learn how to write a Hello World program in Java and create basic Java programs for Calculator etc.
2. Core Java: At this level, you have to gain expertise in Java Collections, Java Multi-threading, OOPS concepts, Polymorphism, Java Exception handling etc. This is the level at which you can get a Job in a company.
3. Advanced Java: As the name suggests, at this level you are expected to know not only core Java but also related packages etc. You have to know XML handling, JSON parsing, REST service creation etc.

After Advanced Java, you go to architect level of Java. At that level you have to learn frameworks like-Spring, Hibernate, Java Design Patterns etc.

Other Editions of Java:

• Apart from these three versions, there was another Java version released, Java Card. This edition was targeted, to run applets smoothly and securely on smart cards and similar technology. Portability and security was its main features.
• JavaFX is another such edition of Java technology, which is now merged with J2SE. It is mainly used, to create rich GUI (Graphical User Interface) in Java apps. It replaces Swings (in J2SE), with itself as the standard GUI library. It is supported by both Desktop environment as well as web browsers.
• PersonalJava was another edition, which was not deployed much, as its function was fulfilled by further versions of J2ME. Made to support World Wide Web (and Java applets) and consumer electronics. PersonalJava was also used for embedded systems and mobile. But, it was discontinued in its earlier stage.