What is the architecture of jvm ? What is the use of adaptive optimization in java ? What is the role security manager in jvm ?

1. Architecture of JVM contains 

Classloader, Class(Method) Area, Heap, Stack, Program Counter Register, Native Method Stack, Execution Engine

2. Hotspot adaptive optimization

3. The JVM has security mechanisms built into it that allow you to define restrictions to code through a Java security policy file. The Java security manager uses the Java security policy file to enforce a set of permissions granted to classes. The permissions allow specified classes running in that instance of the JVM to permit or not permit certain runtime operations. In many cases, where the threat model does not include malicious code being run in the JVM, the Java security manager is unnecessary. However, when third-parties use WebLogic Server and unknown classes are being run, the Java security manager may be useful.