I've been using .Net now for a few weeks and would like to know if there a
nice solution to my problem.

I got 3 programs which the last one, the user screen, receives data changes
from the second program, in a collection class.

I want to then display this data change on a data grid.

So in short, the third program first gets all the data and then gets only
the changes of the data.
Is there a "easy" way , but more importantly an elegant way of doing this?

Thanks for the help.