Differences between Java 8 and Java 9?

Java 9 version has introduced new enhancements and added new features. It includes JShell, Http2Client, Java Platform Module System (JPMS), Multi-release jar files, Stack Walking API, Private methods in an interface, Process API updates, Collection API updates, Stream API improvements, and etc.

Below are the few differences between Java 8 and Java 9

• In Java 8 and earlier versions, the top-level component is the package. It places a set of related types (classes, interfaces, enums, and etc) into a group, and also contains a set of resources whereas Java 9 introduces a new component: module, which can be used to place a set of related packages into a group, and also another new component: the module descriptor, module-info.java file.
• Java 8 applications use packages as a top-level component whereas Java 9 applications use modules as a top-level component.
• Each Java 9 module has only one module with one module descriptor whereas Java 8 package doesn't build multiple modules into a single module.

Java 8:

Packages  
   - Types (classes, enums, interfaces, etc)
      - Code
      - Data
      - Resources
         - xml
         - images   
         - properties

Java 9:

Modules (Resources, Module Descriptor)
   - Packages
      - Types (classes, enums, interfaces, etc)
         - Code
         - Data
         - Resources
            - xml
            - images
            - properties