Читать книгу OCP Oracle Certified Professional Java SE 17 Developer Study Guide - Jeanne Boyarsky - Страница 59

The Java Development Kit (JDK) contains the minimum software you need to do Java development. Key commands include:

 javac: Converts .java source files into .class bytecode

 java: Executes the program

 jar: Packages files together

 javadoc: Generates documentation

The javac program generates instructions in a special format called bytecode that the java command can run. Then java launches the Java Virtual Machine (JVM) before running the code. The JVM knows how to run bytecode on the actual machine it is on. You can think of the JVM as a special magic box on your machine that knows how to run your .class file within your particular operating system and hardware.