SQL

stuff in sql server

DECLARE @Table1 TABLE(ID INT, Value INT)
INSERT INTO @Table1 VALUES (1,100),(1,200),(1,300),(1,400)

SELECT  ID
       ,STUFF((SELECT ', ' + CAST(Value AS VARCHAR(10)) [text()]
         FROM @Table1 
         WHERE ID = t.ID
         FOR XML PATH(''), TYPE)
        .value('.','NVARCHAR(MAX)'),1,1,' ') List_Output
FROM @Table1 t
GROUP BY ID

stuff in sql server

STUFF(string, start, length, new_string)
SELECT STUFF('SQL Tutorial', 1, 5, 'HTML');
-- output
-- HTMLutorial

stuff in sql

STUFF Function: This function is used to
overwrite existing character or inserts
a string into another string. 

REPLACE function: This function is used 
to replace the existing characters
of all the occurrences.