"Deed" is the term for a document that can act as legal evidence of a property transfer. Many types of deeds contain different levels of legal protection for the new owner in the form of promises that the previous owner (or any owners before him) did not transfer the property to another party. But a quitclaim deed has none of these promises. Quitclaim deeds promise only that the transferring party is handing over his interest in the property; they make no guarantee about how valid that interest might be.
Quitclaim Deed Example
John buys a home from Arthur, and Arthur gives him a quitclaim deed. After two months of ownership, John opens his mail and finds a notice of eviction from Bob. Bob claims that, eight years ago, Michael (the owner before Arthur) actually sold him the home. When John checks, Bob does have a deed to the home recorded with the county. In this situation, had Arthur transferred to John with, for instance, a warranty deed, John could now sue Arthur for damages or (in some states) demand that Arthur work to get him actual, good title to the property. But since John has only a quitclaim deed, the only way he can sue Arthur is if Arthur actually knew of the previous transfer to Bob and committed fraud.
When two people own property in joint tenancy, they each have an equal right to the whole property. They can do anything with it, but cannot use the property in such a way that another joint tenant who wants to use the property cannot. Joint tenancy is an "undivided" interest; no tenant owns a fraction of the property all for himself. Parties wanting to actually divide the property among themselves must go through a judicial process called partition.
Right of Survivorship
Joint tenancy comes with a "right of survivorship." Due to the undivided nature of the property, when one of the joint tenants dies, his ownership interest dies with him. He may not leave his interest to descendants or other parties. For instance, if A, B and C own property as joint tenants, and C dies, A and B now own the whole property as joint tenants.
Deeds and Ownership
A transferring party may use a quitclaim deed to transfer ownership to joint tenants. However, as shown in the example above, these joint tenants will each face the same lack of legal protection as John in a case where the transferring party did not have perfect title to the property. Joint tenants wishing to transfer the joint tenancy property together (as one) may also use a quitclaim deed to do so.