New York apartments come in two types: the Condo and the Cooperative Apartment, and from the exterior of the building, you cannot tell which is which.
A Condo is a property with ownership rights. After signing the sales contract, the owner of the Condo has ownership rights over a certain proportion of the apartment and the common areas of the building. The owner must pay property taxes to the city and common management fees to the apartment's operation committee.
A Cooperative Apartment is different. The entire apartment building is an apartment corporation, and buying an apartment only allows the buyer to own shares of this corporation. These shares grant the buyer the right to reside in the apartment but do not give them ownership of the apartment. The ownership of the apartment resides with the apartment corporation.