Nested DataGridView in windows forms c#

I  started working on creating a Nested DataGridView sample program which should
be useful to all. As a result I have created a Nested DataGridView and you can
find the source code from this article. My aim is to create a simple and easy
program for users. User can download the code and can customize depend on their
requirement.

Why we need Nested or Hierarchical DataGridView

In real time projects like Order Management, Production management and etc.
we need to display the data in the hierarchical result.