Emotional friendship can be one which is built basically due to emotions. This can be a negative as well as a positive friendship.
The people involved in this friendship tend to have a lot of emotional connections with each other which can lead to getting hurt very easily. Th relationship can eventually turn toxic but the because two individuals are emotionally related, getting out of such a relationship can be a task.
However, on the brighter side, the people involved in this kind of a friendship know everything about one another and can act like good support systems, making this friendship very strong and everlasting too.