Grant of easement is a right, annexed to land to utilise other land of different ownership in a particular manner or to prevent the owner of such other land from utilising his land in a particular manner.
Release of easement removes the burden of the easement from the servient tenement.
Right of way is a particular type of easement, ie a right, annexed to land to travel over other land of different ownership in a particular manner.
Release of a right of way removes the burden of the right of way from the servient tenement.