Java SE 6 vs. JRE 1.6 vs. JDK 1.6 - What do these mean?

Navigating through Java versions and terminologies

The Java versioning is sometimes confusing to beginners. To clarify, Java 5.0 is equivalent to Java 1.5 and, likewise, Java 6 maps to Java 1.6. Running java -version gives you three distinct version numbers, each related to the Java Platform, Java Runtime Environment (JRE), and the embedded JIT compiler aka HotSpot version. A critical point to note here is that from Java SE 7, Oracle stopped providing public updates. You'll need to upgrade to an updated Java SE like 8 or later for support and security patches.

Deeper dive into specific components

Java SE: The standard Java platform

Java Standard Edition (SE) sets the base for the building and execution standards in Java. It contains core features and standard APIs, effectively defining the capabilities and limitations of Java.

JDK: The full kit for development

Beyond including the JRE, the JDK provides a comprehensive set of development tools for Java. You will need this if you do any Java coding (so, just about everyone here!). It has tools like javac (the compiler), javadoc (documentation generator), and jdb (the debugger), to mention a few. After you install the JDK, it's good practice to check the JDK and JRE installation directories to make sure everything is set up correctly.

JRE: It’s showtime for Java applications

The JRE is all that's needed for end users who don't create but only run Java apps. It's part of the JDK and enables execution of compiled Java applications.

Into the future: updates and considerations

As we talk about Java SE 6, it's crucial to realize that Java 6 is on its way out. Oracle's policies regarding updates for newer versions like Java SE8 and beyond could change—stay informed through the Oracle Technology Network or other official outlets.