What do you mean by Spring IOC Container?

At the center of the Spring Framework, lies the spring container. It is the container, which creates the object, wires them together, makes necessary changes in them and manages their entire life cycle. The spring container uses the Dependency Injection to manage the elements that the application is made up of. The container gets the instructions for which objects to assemble, instantiate and configure and by reading the modification metadata provided. This metadata is provided either by XML, Java code or Java annotations.