You can use tasks to set up the execution of:
An integration or data migration. In this case, define the messages to be run by the task.
Outbound web services. In this case, define the outbound web service actions to be run by the task.
Batch classes. In this case, define the batch classes to be run by the task.
Master data management. In this case, define the master data entities to be run by the task.
Test cases. In this case, define messages with test cases for the task.
You can use task dependencies to run tasks sequentially or in parallel. If you run tasks in parallel, the performance increases.
You can run tasks:
By running a single task. Usually, you only do so for testing purposes.
By running the related project. All tasks of the project are run.