Why is it called a wake if the person is actually dead?

It is a mourning & viewing period which follows after a person's death, much like the waves which follow a boat in the water.Much likethe ripples produced in the water, so are the memories shared by family & friends in the aftermath of the person's life. A wake is a time to share how the deceased has touched one's life. Check out the dictionary's definition of the Word wake as a noun.