From TOP (Transact-SQL)
Used when you want to return two or more rows that tie for last place
in the limited results set.
Note the example
SQL Fiddle DEMO
We have a table with 6 entires 1 to 4 and 5 twice.
Running
SELECT TOP 5 WITH TIES *
FROM MyTable
ORDER BY ID;
returns 6 rows, as the last row is tied (exists more than once.)
Where as
SELECT TOP 5 *
FROM MyTable
ORDER BY ID;
returns only 5 rows, as the last row (2 in this case) exists only once.