A rose is a round or square backplate that fixes to the door. They mainly come in 55mm wide sizes but the triad range has a 65mm backplate to retrofit over existing holes. With the Futura range, you can purchase larger adapter plates if required to cover a large hole.
A long plate is precisely that. The longplate version of a handle. This also comes in passage, dummy and entrance. The privacy, however, has a privacy turn and comes with a privacy mortice lock.