Mourning is defined as the public display of grief.
While grief focuses more on the internal or intrapsychic experience of loss, mourning emphasizes the external or public expressions of grief.
Consequently, mourning is influenced by one’s beliefs, religious practices, and cultural context.

There is obvious overlap between grief and mourning, with each influencing the other; it is often difficult to distinguish between the two. One’s public expression (i.e., mourning) of the emotional distress over the loss of a loved one (i.e., grief) is influenced by culturally determined beliefs, mores, and values.

National Cancer Institute. Bereavement, Mourning, and Grief (PDQ®). Internet. Accessed on July 7, 2016..