timestamp of record

I think that as soon as I do loaddata(select * from...)
it fills dataset with records and disconnects from server.

Now another user also does the samething and changes the data and updates the record.

Now when I do changes in the same record the other user has saved and try to do save the record it gives the error
"concurrency voilation"

Now I want to know that where does it store this information.
How dows it know that the record has updated by some one else?

In the dataset. I don't believe you can get to the data though. If it is a strongly typed dataset then you can probably see the code by viewing the code for the dataset.

then how does it know that the record has changed by another program?