What is dependency injection in Angular?

[akhils-nair-b6a2a78b (Akhil S Nair)]

Dependency injection (DI), is an important application design pattern in which a class asks for dependencies from external sources rather than creating them itself. Angular comes with its own dependency injection framework for resolving dependencies( services or objects that a class needs to perform its function).So we can have our services depend on other services throughout our application.