The Java programming language lets you include comments in the source code that can be used to prepare documentation for the application. Such comments are known as documentation comments or Javadoc comments. JDK provides a javadoc command-line tool to extract the documentation comments from the source codes and generate documentation in HTML format. The javadoc tool is located in the bin directory of the JDK_HOME directory. For example, if you have installed the JDK in C:\java8 directory, the javadoc tool will be located in the C:\java8\bin directory.