Tasks are all the things that actually need to be worked on, whereas task lists only serve as categorisation. You can define as many tasks as you like and assign them to milestones, lists and make them depend on other tasks as well. Basic and self-explanatory form fields such as Title and Description are not covered here.
Project
When creating a new task, you must select a parent project. Once you save it, the project can no longer be changed. The selected project will unlock and govern the available milestones, lists, labels and access groups you can select in this form. So its a good idea to select a project first, before continuing through the rest of the form.
Milestone
You can optionally assign the task to a milestone. If you do so, the milestone may influence which task lists and user groups for permissions are available. It can also affect the available selection range for the start and end date fields.
Task list
Selecting a list is optional. If you do, it may influence which user groups for permissions are available.
Labels
Labels will become available once you've selected a project. Then you can select one or multiple items from the list. The labels that are available to you is determined by the defined global and task labels of the selected project.
Status
In the site frontend, only published items will be visible to non-admins.
Start and End date
Based on which project or milestone is selected, and assuming they have a start or end date set, you can only select dates that are within range of the parent milestone or project. For example if your selected milestone ranges from 1st until 10th, you'll only be able to select dates that is within this time period.
Hourly Rate
Here you can enter the rate you work for on this task per hour. This information will be used in the time tracker.
Estimated Time
The estimated time it will take for you, or the assigned people to complete this task. This information will be used in the time tracker.
Assigned Users
Here you can assign the task to one or multiple people. If no one is selected, anyone will be able to complete this task. Otherwise, this option is limited to the people assigned to it.
Dependencies
Allows you to make the task depend on other tasks to be completed first.Attachments
This field will become available after you've selected a project. If you disabled the file repository extension, this part of the form will not be available. The files that you attach here will be visible on the task details page.
Permissions
In order to see and change the permissions, you have to be an administrator. Non-Admins will not be able to set the task permissions. Instead, the access of the selected parent item (list, milestone or project) will be inherited. If you are an admin, the groups that are available for selection is limited by the access of the selected parent item - again, list, milestone or the project. For example, if your selected project has selected the "Registered" group, you will not be able to select the "Public" group here, because it lies outside the containment.