Data is laid out in a column-wise format, instead of row-wise. This speeds up processing the data, at the cost of making it slower to insert rows (assuming that’s even allowed).

<class 'pandas.core.frame.DataFrame'> RangeIndex: 5560 entries, 0 to 5559 Data columns (total 10 columns): Tow Date 5560 non-null datetime64[ns] Make 5537 non-null object Style 5538 non-null object ...