Actual performance of a task is called
The actual performance of a task is called an Activity.
An activity is the actual performance of a task. The preceding event is called the "tail event and the following is called the "head event'.
The activities are classified into four categories
Predecessor activity:- Activities that must be completed immediately prior to the start of another activity are called predecessor activities.
Successor activity:- Activities that can't be started until one or more of the activities are completed but immediately succeed them are called successor activities.
Concurrent activity:- Activities that can be accomplished simultaneously are known as concurrent activities.
Dummy activity:- An activity that does not consume any resource but merely depicts technological dependence is called a dummy activity.