Specific components of a particular activity are known as activity attributes. In the beginning, these are typically descriptive factors related to the specific activity, but they can also describe activities that will become more relevant later in the project timeline.
Most activity attributes can be organized, sorted and summarized. This happens based on a few specific categories. A few of the categories for activity attributes are activity codes, the specific people involved in the activity, locations for the activity, the time and costs required for completion, etc. It helps to organize the activity attributes into similar categories. The various components that are a part of each activity can be described to further extend the activity attribute.
Frequent uses for activity attributes are to recognize the specific people who will be handling specific pieces of the work or to specifically state where the work will be carried out. Other uses include indicating the effort levels that will be required. These include LOE (level of effort), discrete effort, or AE (apportioned effort). Developing a schedule that will identify when planned activities will be selected, ordered and sorted is another use of activity attributes. There is always a difference in the number of attributes based upon the application area.
The PMBOK Guide discusses this topic in section 18.104.22.168 of the fourth edition.