Why do we need different variable types?

The difference between the text and the numeric types is straightforward; however, the main reason for having three types of numeric values is the storage efficiency. For most data files, that is not important and, thus, using the default (Double) data type is recommended. However, for very large data files, being able to switch to a 2 (or even 8) times more efficient storage (by using different data types) could make a difference between being able to perform the necessary analysis on a specific computer system or not. For further details, see Variable Types.