The Standards and Guidelines are a tool used to help decide how best to conserve a historic place by understanding why that place is significant. The guidelines address four types of resources: cultural landscapes, archaeological sites, buildings, and engineering works, as well as materials. Conservation practitioners operate in a ‘values-based context’ to identify and manage historic places according to an evaluation process. These values generally include the aesthetic, historic, scientific, cultural, social and/or spiritual importance of a place. The heritage value of a historic place is embodied in its character-defining materials, forms, location, spatial configurations, uses and cultural associations or meanings.