Dependency Injection is a software design pattern used in Drupal CMS that allows for the decoupling of components from each other. It is a way of providing a component with its dependencies, rather than having the component look for them itself. This makes it easier to maintain and test the code, as well as making it more flexible and extensible.

In Drupal, Dependency Injection is used to provide components with the services they need to function. This is done by passing the services as arguments to the component's constructor. This allows the component to be used in different contexts, as the services can be changed without having to change the component itself.

Dependency Injection is also used to provide components with configuration options. This is done by passing a configuration object to the component's constructor. This allows the component to be used in different contexts, as the configuration can be changed without having to change the component itself.

Dependency Injection is an important part of Drupal's architecture, as it allows components to be decoupled from each other and makes it easier to maintain and test the code. It also makes it easier to extend and customize the code, as components can be easily replaced with different implementations.