The JRE runs code inside a "sandbox." This means that if you download a Java applet from a website, the JRE restricts what that code can do. For example, it may prevent the code from accessing your local hard drive or executing harmful system commands. This security layer is provided by the JVM within the JRE, protecting your computer from malicious software.
This modular design:
| Tool | Purpose | |------|---------| | jps | List Java processes | | jstat | JVM statistics (GC, compilation) | | jmap | Heap dump generation | | jstack | Thread stack traces | | jcmd | Send diagnostic commands to a running JVM | | jinfo | JVM configuration flags | what is java jre