Introduction In software engineering, dependency injection is a technique that enables a class or module to receive its dependencies from an external source rather than creating them itself. This approach decouples the code from external dependencies, making it easier to test and maintain. What is Dependency Injection? Dependency Injection (DI) is a design pattern that helps you decouple the code by passing dependencies to a class or module. It is a technique where one object supplies the dependencies of another object. It is a way to achieve loose coupling between objects and makes it easier to test, maintain and extend your code. How to Use Dependency Injection with Examples Let's take a look at an example of how to use dependency injection in C# code. Suppose we have a class called UserService which is responsible for creating and managing user accounts. The UserService class requires a UserRepository object to interact with the database. public class UserService {