This legal expression has nothing to do with renting property but relates to
buying a home. When you buy a property with a partner you have a choice of ownership.
The most common, as Joint Tenants, means you
share the obligations of ownership equally. Accordingly, on death, the surviving
partner automatically inherits the whole property. The alternative, Tenants
in Common (q.v.), means you only own a pre-agreed share of the property (usually
50% of course). However, on your death, this share can be willed separately and
need not necessarily be left to your partner.