What is a tenancy in common and how does it differ from joint tenancy?

Tenancy in common allows two or more people to own undivided interests in the same property, where each owner can hold unequal shares and independently sell, transfer, or will their interest. Joint tenancy requires equal ownership shares and includes the right of survivorship, meaning when one owner dies, their share automatically passes to the surviving owners rather than to their heirs. Joint tenancy requires four unities: time, title, interest, and possession. Tenancy in common requires only unity of possession.