What is the use for Dependency Injunction in Angular?

Question

Every angular project is required for Redux ? or only required for large applications.

Answer 1

Dependency Injection (DI) is a way to create objects that depend upon other objects. A Dependency Injection system supplies the dependent objects (called the dependencies) when it creates an instance of an object.
Dependency Injection (DI) was a core feature in Angular 1.x, and that has not changed in Angular 2. DI is a programming concept that predates Angular. The purpose of DI is to simplify dependency management in software components.