Data types
In CSV files, all values are strings. This is not particularly true to the data, but it is simple: everything is a string.
The underlying data in Excel spreadsheets is more complex. A cell can be one of four things:
A boolean, like TRUE, FALSE, or NA.
A number, like “10” or “10.5”.
A datetime, which can also include time like “11/1/21” or “11/1/21 3:00 PM”.
A text string, like “ten”.