The Boolean Data Type has two potential values: TRUE and FALSE. It used to answer "Yes"/"No" questions. For example, a Checkbox component uses a Boolean value to determine whether or not it should be displayed with a check or not.
Booleans are also useful for the conditional IF function. For example, the function ISNUMBER will return TRUE if the argument is a Number Type, and FALSE otherwise. One can use this function combined with IF to conditionally perform some operation depending on if a value is a Number:
IF(ISNUMBER(my_variable), FORMAT_NUMBER(my_variable, "#"), "Not a number")