The dependency is passed/injected to the dependent by the injector[Spring container].
An injection is the passing of a dependency to a dependent object (a client) that would use it
Passing the service to the client, rather than allowing a client to build or find the service, is the fundamental requirement of the pattern
Dependency injection allows a program design to follow the dependency inversion principle. The client delegates to external code (the injector) the responsibility of providing its dependencies. The client is not allowed to call the injector code. It is the injecting code that constructs the services and calls the client to inject them. This means the client code does not need to know about the injecting code. The client does not need to know how to construct the services. The client does not need to know which actual services it is using. The client only needs to know about the intrinsic interfaces of the services because these define how the client may use the services. This separates the responsibilities of use and construction.