In a condo building units are separate properties with their own deed that can be bought and sold.
With a co-op the building is owned by a corporation. Units are rented from the corporation and the” owners” are the shareholders in the corporation and elect it’s board of directors.
In a co-ownership, title to the building is held by all of the co-owners who occupy units in accord with an agreement to which they are all parties. The agreement allow for the co-owners to elect a board & manage the co-ownership . Units in the co-ownerhsip are not separate properties and cannot be individually sold.