Estates are divided, as regards the number of owners, into estates in severalty and joint estates. An estate in severalty is one where there is individual ownership. An estate of this character needs no further explanation. Joint estates include all those estates where two or more persons have a right of ownership or possession in the same land at the same time. Joint estates are subdivided into joint tenancies, estates in common, estates in entirety, estates of coparcenary, and estates held by partnerships.