A right benefiting a piece of land (known as the dominant tenement (www.practicallaw.com/resource.do?item=:20749555)) that is enjoyed over land owned by someone else (the servient tenement (www.practicallaw.com/resource.do?item=:20749723)).
Usually, such a right allows the owner of the dominant tenement to do something on the other person’s land, such as use a path, or run services over it. This type of easement is sometimes referred to as a positive easement. More rarely, an easement will limit what the owner of the servient tenement may do on the land. For example, the owner might not be allowed to construct buildings that would interfere with someone's right to light. This type of right is sometimes called a negative easement.