They are different forms of ownership. A condo is real property like a house. A coop is considered personal property not real property. In a coop you own shares in the housing corporation allocated to a particular apartment. Coops can have an underlying mortgage where each shareholder pays a portion of the underlying mortgage in their maintenance. Condos can not have an underlying mortgage. There are pros and cons of both forms of ownership. Condos cost more and have significantly higher closing costs. Coops cost less but usually require a larger down payment. For many buyers coops offer more of a "quality of life" community. More about coops and condos linked below including a downloadable version of my Manhattan coop and condo buying guide.