Celebrant

Its a legal requirement in the UK, that you must sign the marriage license in front of a Registrar or Priest, however the exchange of vows and rings are just for ceremonial purposes and not a legal requirement.
Ceremonies led by the registrar can be impersonal and there are restrictions in terms of content.

A Wedding led by a Wedding Celebrant, allows you the chance to have your ceremony the way you want, personal, about you, to your timing and your choice of location, with no restrictions.