Java.exe and Javac.exe, what is the relationship between the JVM and what is the role of environment variables

Javac a Java file into a binary file
Java Run binary file produces results

JVM Java Virtual machines, providing a running environment for Java compilation operations

What is the role of environment variable environment variables

The environment variable contains the information that one or more applications will use, and when the system is asked to run a program without telling it the full path of the program, the system should also go to the path specified in paths, in addition to finding the program under the current directory. The user can run the program better by setting the environment variable. Here's a look at the setting of environment variables in the WinXP system. In order to illustrate the problem, we use the "QQ Chat program" of the setting of environmental variables for example to explain.