What is Spring configuration file?

Spring configuration file is an XML file. This file contains the classes information and describes how these classes are configured and introduced to each other. What is Dependency Injection? Inversion of Control IoC is a general concept, and it can be expressed in many different ways and Dependency Injection is merely one concrete example of Inversion of Control. This concept says that you do not create your objects but describe how they should be created. You don't directly connect your components and services together in code but describe which services are needed by which components in a configuration file. A container theIOCcontainer is then responsible for hooking it all up.