Sigel Landlord-Tenant Lawyer, Pennsylvania

A legal doctrine stating that if a person receives money or other property through no effort of his own, at the expense of another, the recipient should return the property to the rightful owner, even if the property was not obtained illegally. Most courts will order that the property be returned if the party who has suffered the loss brings a lawsuit.

A person to whom a property right is transferred. For example, an assignee may take over a lease from a tenant who wants to permanently move out before the lease expires. The assignee takes control of the property and assumes all the legal rights and responsibilities of the tenant, including payment of rent. However, the original tenant remains legally responsible if the assignee fails to pay the rent.

Land and the property permanently attached to it, such as buildings, houses, stationary mobile homes, fences and trees. In legalese, real estate is also called real property.

A right to use property, acquired by a long tradition of open and obvious use. For example, if hikers have been using a trail through your backyard for ten years and you've never complained, they probably have an easement by prescription through your yard to the trail.

A way for married couples to hold title to property, available in Arizona, California, Nevada, Texas and Wisconsin. It allows one spouse's half-interest in community property to pass to the surviving spouse without probate.

A non-U.S. citizen who has been given permission to make his or her permanent home in the United States. If you acquire permanent residence, you will be issued a green card to prove it. The terms permanent resident and 'green card holder' mean exactly the same thing. You cannot be a permanent resident without a green card and you cannot have a green card without being a permanent resident. As a permanent resident, you may travel as much as you like, but your place of residence must be the United States and you must keep that residence on a permanent basis. If you leave the United States and stay away for more than a year, you risk losing your green card.

A right to property that cannot be enforced in the present, but only at some time in the future. For example, John's will leaves his house to his sister Marian, but only after the death of his wife, Hillary. Marian has a future interest in the house.

In a contract, a promise by one party not to hold the other party responsible if the other party carries out the contract in a way that causes damage to the first party. For example, many leases include a hold harmless clause in which the tenant agrees not to sue the landlord if the tenant is injured due to the landlord's failure to maintain the premises. In most states, these clauses are illegal in residential tenancies, but may be upheld in commercial settings.