In real estate, an easement is something which gives someone the right to use land which does not belong to him or her for a set and specific purpose. Common examples of easements include utility poles on private land and shared driveways. Depending on how an easement is set up, it may be integrated into the deed for a property, making it permanent, or it may be a temporary measure which has an expiration date. In general, easement use of land must not be in conflict with use by the legal owner.

There are numerous different types of easements. Most break down into two categories: easement appurtenant and easement in gross. In the case of an easement appurtenant, the easement is an agreement between two neighboring landowners which may benefit both. For example, a landowner may be granted an easement to run a ditch through a neighbor's property for drainage. Because the ditch can be used by both landowners to prevent flooding, it is a beneficial agreement. Other instances of an easement appurtenant are simply agreements between neighbors, such as one neighbor granting another neighbor permission to cross his or her property to reach a state park.

An easement in gross, on the other hand, is only attached to one property, not to neighboring properties. The most typical example of an easement in gross is a public utility easement, which allows a utility to run water, power, gas, or sewer lines through private property. Deeded Coastal Access is another type of easement in gross, allowing members of the public to cross private land to reach a beach or shoreline.

An easement is not a lease or a license. A lease gives someone much more control over a piece of land, in exchange for payments of cash at set intervals. A license is a specific permission to do something, such as park a vehicle, but it can be revoked at will. Cancellation of an easement requires more work, although it is possible. Typically, an easement is a written agreement, although it can also be implied. For example, if someone has been using a neighbor's property to access something for an extended period of time, an easement is assumed, and the affected landowner must actively work to end the easement, if that is desired.

An easement can be used to grant permission to do something, or it can restrict a landowner. A permissive easement is the more common type. Restrictive easements may limit development, prevent someone from building a house over a certain height, or limit other activities on the land. These types of easements are not uncommon in planned communities, to ensure a uniform look and feel for the community.

Historic and conservation easements also exist. These easements are aimed at preserving valuable resources and history for society in general. They usually limit development and activities which will be permitted on the land in question, and are donated by the landowner. In most cases, a trust is established to care for the land.