Why do I need to instantiate object?

Question

Hi

I have the following code:-

IOrderedDictionary rowValues = new IOrderedDictionary();

rowValues = GetValues(GridView1.Rows[i]);

CheckBox cbRemove = new CheckBox();

cbRemove = (CheckBox)GridView1.Rows[i].FindControl("Remove");

My question is why do I need to create a instance\object of the IOrderedDictionary and CheckBox classes?

I changed the code to 

IOrderedDictionary rowValues;

rowValues = GetValues(GridView1.Rows[i]);

CheckBox cbRemove;

cbRemove = (CheckBox)GridView1.Rows[i].FindControl("Remove");

And found that it still works at both compile and runtime?

Regards
Steven