In mathematical sets, the null set is a set that does not contain any values or elements. It is expressed as { } and denoted using the Greek letter ∅ (phi). A null set is also known as an empty set or ...

A value in a field or variable that indicates nothing was ever derived and stored in it. For example, in a decimal-based amount field, a null value might be all binary 0s (null characters), but not a ...