Usually aggregated... then can start looking at "subsets". For example, step 1 is look at the whole dataset. Then you identify that there are a lot of rows with a type of missing value, so you look at the statistical attributes of that subset (all the rows with value X in null).

From time to time you can do a `.head()/.title()` or an `.iloc[X:Y]` to check some things visually. But just as a "refresher".