Joint tenancy exists where two or more persons all gain title under the same disposition (such as a conveyance) at the same time. In a joint tenancy, all owners hold the same interest and are simultaneously entitled to possession and enjoyment of the whole property. They do not own any particular share (such as a half or a quarter) of the land. Married persons often hold land together as joint tenants.
Joint tenants also have a right of 'survivorship', which means that when one joint tenant dies, the other tenant becomes the sole owner.
Tenancy in common
Tenancy in common exists when there is separation of ownership, so each tenant owns a particular share (such as a half or a quarter) of the property. As with joint tenants, tenants in common are simultaneously entitled to possession and enjoyment of the property. But they do not gain title under the same disposition, and there is no right of survivorship.