VISITATION
A viewing means to have an open casket.

A visitation offers a chance for people to "pay their final respects." 

Just as important, the visitation can be a time for mourners to meet and console each other in a more informal setting than at the funeral.

The visitation can be restricted to just close friends and family, or be open to the public. You can even have a combination of private and public hours.

Is there a special ceremony?

As part of the visitation, you can arrange a formal ceremony, an informal ceremony, or none at all. The formal ceremony might be a brief service with the saying of the rosary (for Catholics) or prayers for the dead led by a mourner or member of the clergy.