Your activities are all meetings, calls, etc that are part of closing business. You can access a log of all activities from your main menu, and can assign activities to specific deals from your pipeline as well.
Buzzflow will keep track of all your activities and tasks and will provide you with a reminder and also maintain records of all activities taken.
This feature is extremely useful for a team to stay updated on the progress being made. For a more detailed look at how to use the activities feature click here.