Angular Ivy is a next-generation compilation and rendering pipeline, which reduces the bundle size, loads faster in slower networks and is simple to use. Ivy is still in an experimental phase and is expected to be available in Angular version 8.0.

Ivy is the code name for Angular's next-generation compilation and rendering pipeline. With the version 9 release of Angular, the new compiler and runtime instructions are used by default instead of the older compiler and runtime, known as View Engine.

Please refer links
1) https://angular.io/guide/ivy
2) https://blog.angular.io/a-plan-for-version-8-0-and-ivy-b3318dfc19f7
3) https://blog.ninja-squad.com/2019/05/07/what-is-angular-ivy/
4) https://medium.com/angular-in-depth/all-you-need-to-know-about-ivy-the-new-angular-engine-9cde471f42cf