Assigning a blog to a tribe tells the system which blog's content should be imported into a specific tribe's stream. Please note, if only one blog is connected you are still required to assign the blog to a tribe if you want your blog posts to import into that tribe.
Reminder You can only change the blog a tribe is assigned to once every 30 days.
Tribe Sharing Settings
Assigning a social network or networks to a tribe determines the connected social network or networks your post will be shared to, when you add a post to queue from that specific tribe's stream.