What is DI Container

A DI Container is a framework to create dependencies and inject them automatically when required. It automatically creates objects based on request and inject them when required. DI Container helps us to manage dependencies with in the application in a simple and easy way.
Dependency Injection (DI) is a software design pattern that allow us to develop loosely coupled code. DI is a great way to reduce tight coupling between software components. DI also enables us to better manage future changes and other complexity in our software. The purpose of DI is to make code maintainable.
The Dependency Injection pattern uses a builder object to initialize objects and provide the required dependencies to the object means it allows you to “inject” a dependency from outside the class.
We can also manage an application dependencies without a DI Container, but it will be like as POOR MAN’S DI and we have to do more work, to make it configured and manageable.
For example, Suppose your Client class needs to use a Service class component, then the best you can do is to make your Client class aware of an IService interface rather than a Service class. In this way, you can change the implementation of the Service class at any time (and for how many times you want) without breaking the host code.