Difference between Bit and Boolean datatypes in PostgreSQL
A bit only stores the numbers 0 and 1 (or null).
A boolean only stores true and false (or null). A number (0, 1) is not a boolean. A boolean value can be used anywhere a boolean expression is expected. So you can e.g. do this:
where is_active A bit column needs to be compared to something:
where a_bit_column = 0(the result of a_bit_column = 0 is a boolean)
Contrary to the what some DBMS think, the expression where 0 or where 1 is not valid boolean expression.