The node properties, also referred to as the node’s metadata, contains the majority of the information for a node. The sys:store-protocol, sys:store-identifier, and sys:node-uuid properties contains all the data needed to construct the NodeRef, uniquely identifying the node. The special property called cm:content points to where the physical content file is stored on disk (unless it is a folder or other contentless node type). All properties are either contained in a type or in an aspect defined in a content model. When a node is created some properties are automatically set by the system and cannot be easily changed, they are called audit properties (from the cm:auditable aspect) and are Created Date, Creator, Modified Date, Modifier, and Accessed. Defining new domain specific node properties, together with the types and aspects that contain them, is the primary way of classifying a node so it can be easily found via searches.