Java Development Kit (JDK)

You now know three building blocks: source code, the compiler (javac), and the JVM. But where do you actually get these tools? The answer: you install the "Java Development Kit", or JDK for short.

The JDK is a complete package for developers. It contains everything you need to write and build Java programs: the compiler (javac), the JVM for testing your program, plus additional tools and libraries (ready-made code building blocks that others have already written).

javac Main.java   // Part of the JDK: translates source code into bytecode
java Main          // Part of the JDK: executes the bytecode

Anyone who wants to write and compile Java programs installs the ____.

You can think of the JDK like a complete workshop: it contains not just the machine that uses the finished workpiece (the JVM), but also all the tools needed to actually produce the workpiece in the first place (the compiler and more).

What is included in the JDK (Java Development Kit)?

Without the JDK you might still be able to run finished Java programs (often less is needed for that), but you cannot compile your own source code. So if you want to write your own Java programs, you need the JDK on your computer.

You need the JDK to compile your own Java source code.

In the next lesson you will learn about the JDK's counterpart: the JRE — designed for anyone who only wants to run Java programs, without developing them.