A datatype is not a concept exclusive to programming languages. Excel is a tool and yet you can set a cell's datatype (called category in Excel) to Number, Date, Percentage and a few others.
Different transformations support different datatypes, but here's a list for an expression:
•bigint
•binary
•date/time
•decimal
•double
•integer
•nstring
•ntext
•real
•small integer
•string
•text