Hi
I am not sure about your question and i can guess that you asked for what is the need for the function RowCommand in the grid view.
If so means let me explain with an example.
Consider a grid that contain Edit and Delete Button in every row of the grid.
If you want to delete/Edit the content of the particular row, then you have to click the corresponding Edit/Delete button.
In that scenerio, GridView RowCommand Event fired out.
Hope you understand.
Thanks.