Overlapping sets: Two sets are called overlapping if they have at least one element in common.
Ex. The sets {2, 3, 4} and {3, 6, 9} are overlapping as the element 3 is common to both of them.
But,
Disjoint sets: If two sets A and B have no elements in common, they are called disjoint sets.
Ex. A ={ set of vowels} B = { set of consonants} are disjoint as they have no letter in common.