Extra Practice - Reddit Q9 & Q10

Hi,
Im curious to know, what the difference is between the following 2 answers Q9,Q10

SELECT 
  posts.title, 
  subreddits.___ AS 'subreddit_name', 
  MAX(___) AS 'highest_score'
FROM posts
INNER JOIN ___
  ON posts.___ = subreddits.___
GROUP BY subreddits.id;
SELECT 
  subreddits.___, 
  AVG(posts.___) AS 'average_score'
FROM ___
INNER JOIN posts
ON subreddits.id = posts.subreddit_id
GROUP BY subreddits.name
ORDER BY 2 DESC;

Why is the first group by made with ID while the second group by is with NAME?
Arent both the same?

Thanks

It might help if you linked the lesson as it may not be obvious to anyone who reads this what Q9 and Q10 are, without that info and with an incomplete query it’s just guesswork.