They are a sub-level of projects which means you can now allocate your working times more accurately.
Here is an example how it works:
Imagine you have to build a house. This would be your project. However, the construction of a house can be broken down into many smaller parts: Planning, pouring the foundation, walls, floors, the roof, painting, carpentering, plastering, etc. These are your TASKS.
While your employees are working on a specific task, their working time will still be allocated to the PROJECT. You can now select a task conveniently and directly in the tracker below the Project field.
Please note: If you choose not to assign tasks to a project, the TASK field will be hidden.