Java SE lets its users develop and deploy Java applications on desktops and servers, as well as embedded environments. Java SE contains the core of the Java programming language libraries.
The components of Java SE are Java Development Kit (JDK), Java Runtime Environment (JRE) and Java SE application programming interface (API). JDK contains the JRE and the compilers and debuggers necessary for developing applets and applications. JRE provides the libraries, the Java Virtual Machine (JVM) and the components needed to run Java applets and applications. (See graphic below)
Answer to TEST YOUR KNOWLEDGE: When you're just learning Java, it is often useful to check your understanding of key features as you progress in your studies. To help you do that, we asked Herb Schildt, the author of the bestselling Oracle Press book "Java: The Complete Reference", to provide several questions that test your knowledge of three core topics that all Java programmers must master: data types, variables, and arrays. For detailed information related to these, and the many other features of the Java language, see Herb's comprehensive book, Java:The Complete Reference, 9th edition.