Which countries have oil stockpiles?

I was looking at data on the Energy Information Administration's website on global production and consumption of crude oil and noticed that in many years consumption exceeds production -- from 1980 to 2019, there's a total difference of 2.4 billion barrels. Does this mean there are already reserves of oil that have been extracted in previous years and stored?

But, when I look up what "oil reserves" are on Investopedia, it says:

Oil reserves are an estimate of the amount of crude oil located in a particular economic region. To qualify, oil reserves must have the potential of being extracted under current technological constraints. Reserves are calculated based on a proven/probable basis, meaning oil pools situated in unattainable depths, for example, would not be considered part of a nation's reserves.

So, my questions are:

1. What are barrels of oil that are already extracted and sitting around waiting to be used called?
2. Which countries have these already-extracted oil reserves, and how big are they?
3. Does this storage account for the difference between production and consumption?