You say, “What a silly question! There is no difference.” I kind of agree. One definitely can’t tell any difference, from the data itself. They are the same in this sense. But are they exactly the same? Well, one is the original and the other a copy. “What a silly answer! “, you say.
Maybe it is not as silly as it looks! Ask yourself the following two questions:
If the original data changes, is it still the original? The answer is surely “Yes”.
If the copy changes, is it still a copy? The answer is clearly “No”.
Well, here is some difference! But if we can’t find any difference in the data itself, where does the difference lie? Intuitively, it seems that somehow the difference lies in the “derivative” of the data, evident only when changes happen. Bingo! The “derivative” of data is really its meta-data. So, the difference between data and its exact copy lies in their respective meta-data, particularly, their originations: the data was originated from the original data generating process, while the copy was from making a copy of the original data.
“So, you got me. What’s the big deal?”, now you say. Well, this inability to tell the difference between data and its copy in our systems directly leads to “possession=ownership” being true in our systems. This is the root cause for all our cyber security problems and is also the reason why no system has genuine intelligence yet. Sounds like a big deal to me. Stay tuned…