STUFF sql server

 https://stackoverflow.com/questions/31211506/how-stuff-and-for-xml-path-work-in-sql-server

STUFF( source_string, start, length, add_string ) Parameters or Arguments source_string The source string to modify. start The position in the source_string to delete length characters and then insert add_string. length The number of characters to delete from source_string. add_string The sequence of characters to insert into the source_string at the start position.

SELECT ID,
    abc = 
    STUFF (
        (SELECT   
                ',' +Name  
        FROM temp1
        FOR XML PATH('')), 1, 1, ''
    )
FROM temp1 GROUP by iD

Output:
-----------------------------------
| Id        | Name                |
|---------------------------------|
| 1         | aaa,bbb,ccc,ddd,eee |
-----------------------------------