what's the difference between take part in and join in?

what's the difference between take part in and join in?
what's the difference between take part in and join in?

what's the difference between take part in and join in?
take part in的主语是活动的主要参加者（主体）：Three teams took park ( in the game).不谈具体参加内容时,不用in短语.
join 和join in的意思是,在别人进行活动时的加入者（客体）：We are playing basketball .Come and join us.
join的宾语一般是人、团体、组织等；join in的宾语一般是活动.