No notification from specific friends when they post activities
I would like to receive(push/email) notifications from all my friends whenever they post an activity but I don't receive push/email notifications when some of the people I follow (friends) post an activity.
I follow both "X" and "Y"
when "X" add an activity I got a notification your friend "X" posted a new activity
But when "Y" add one I got nothing. But If I go to "Y" profile I can see all his activities so the activity is visible to me
Any idea why this happen
One more thing I am very confused between a person I follow and he follows me back and Friend.
Can you explain the difference and if there is no difference please be consistent and use the same concept and name