Difference between INTERSECT and INNER JOIN?

Sno	Intersect	Inner join
1	It is SET operator	It is JOIN operator
2	It return duplicates	It remove duplicates
3	It never return NULL values, If exists	It return NULL values, If exists
4	It matches Limited set of columns	It compares all rows between two sets

Examples:

CREATE TABLE #a (id INT)

CREATE TABLE #b (id INT)

INSERT INTO #a VALUES (1), (NULL), (2)

INSERT INTO #b VALUES (1), (NULL), (3), (1)

select * from #a                    select * from #b

#A	#B
id	id
1	1
NULL	NULL
2	3
	1

1)select #a.id from #a INNER JOIN #b on #a.id=#b.id

         o/p) 1

                 1

2) select * from #a INTERSECT  select * from #b

       o/p)  NULL

               1