union It contains all the elements contained in both sets. (A ⋃ B) a={'red', 'green', 'blue'} b=set(['red', 'yellow', 'orange']) a_union_b=a.union(b) print(a_union_b) >>> {'blue', 'green', 'red', 'yellow', 'orange'} intersection It contains only the elements that are in both sets. a_intersec_b=a.intersection(b) print(a_intersec_b) >>> {'red'}