Elegy:

Elegy

Definition: A sorrowful, mournful and plaintive poem, usually lamenting the death of someone

Example:  

The curfew tolls the knell of parting day,
The lowing herd winds slowly over the lea,
The ploughman homeward plods his weary way,
And leaves the world to darkness and to me.

Significance:

Elegies express the feelings, mercy, grief, and laments of poets for the death of their beloved ones. Instead of hiding all the sorrow and pain, people can express all of them through writings.