An easement is the right for someone to use your property but not have ownership.
A right of way is a type of easement. In New England, it may be common to find a right of way to access the waterfront. In this case, the right of way is a public easement granting access to the public to gain access to the beach or lake front. A right of way can also be granted to an individual or an abutting piece of property.
Another common easement is a utility easement. With a utility easement, you grant a utility company rights to run service across your land and maintain that service as well. Many easements are in place when you buy a home and are a permanent right unless both parties agree to terminate the easement.