Property refers to those descriptive features of an entity or action, either in its singularity in the case of an instance at a moment in time, or in plurality when criterial features are captured within a concept in order to define the shared features of more than one entity or action. They are adjective-like in the case of entities, or adverb-like in the case of actions. Properties may be variable in the case of an entity which is the subject of action, or capture the range of variability across instances within the scope of a concept. Properties may refer to qualities or quantities.