In project management, a task is an activity that needs to be accomplished within a defined period of time or by a deadline to work towards work-related goals.
The main driver is the tasks. The tasks can represent different things, depending on your need. Normally a task represent an activity, which should be performed by a member in the project.
A task can also represent a reminder, like a milestone, to ensure that all participants in the project work towards this.
It is possible to work with tasks in different ways. There are 4 main views:
It is specificed in the project settings, what each individual user can do with the task. This includes adding new tasks, editing or deleting tasks.
There is a detailed history bound to the tasks. You can always track who changed what and when.
Furthermore there is a dialog field. All project participant, not matter thier user restrictions, can add comments to the dialog field.