The Activity Index (ACTV) window displays valid codes and classifications for activities. An activity is an internal program that you want to define for budgeting and/or reporting purposes. Activities can cut across organization and fund boundaries. For example, more than one organization can spend money for the same activity, and more than one fund can supply money for the same activity.
The activity code is the starting point for a classification hierarchy that puts similar activity codes together in progressively larger groups. Similar activities make an activity class, similar activity classes make an activity category. The entire classification scheme (including activity) is optional. You might not use it at all, or it might only use a part of it.