Ownership of real estate by a single party is called

individual ownership.

solitary possession.

tenancy in severalty.

simple tenancy.

The owner of a unit within a cooperative actually owns

shares in a corporation or association and a proprietary lease in a physical unit.

a fee simple interest in a physical unit plus a tenancy in common in common elements.

a tenancy in common in a physical unit and the common areas.

a ground lease in the physical unit's pro rata share of land and a proprietary lease in the unit.