Usually a smaller structure dedicated to a single deity or Exarch, a shrine is a religious site, similar to a Church. Sometimes in a larger Church, there will be one or more shrines to related beings. A Dragonborn church to Bahamut might have a shrine to Kuyutha.
If a shrine isn’t part of a larger structure, it’s very rare that it will have any staff to care for it. In these cases, the community closest to the shrine takes care of it.