An activity is a general purpose screen that captures information on appointments, emails, letters, faxes, phone calls, tasks (to dos) or any other type of activity you want. For example you might of had 3 phones calls, sent 2 emails, and have one scheduled appointment with this contact. You decide how much data you want to track. Activities can be linked to contacts, employees, campaigns, events or any combination of those 4 entities. You can also have attachments on each activity.