explain output clause in sql code example

Example: sql insert inserted id

-- Never use @@identity or scope_identity()
-- they can not always be relied upon

DECLARE @Ids_tbl TABLE ([id] INT); -- Requires table. use variable for scope
INSERT INTO [sometable] ([ColA],[ColB])
OUTPUT INSERTED.ID INTO @Ids_tbl(id)
VALUES ('valA','valB');

SELECT [id] FROM @Ids_tbl; -- <-- Id(s) in here