A task will always have the following states.
The task has been created but has not been assigned to a user or group to begin work. Creating a task is described in the section called “Creating Tasks”.
The task has been assigned to a user or group. Assigning a task is described in the section called “Task Operations”.
The developer has started work on the task. The developer starts work on a task within the My Tasks view. This is described in the User Guide 'My Tasks View' chapter.
The task has been completed. A task is completed when a user submits a changeset with a task. A task can also be completed by right-clicking on a task and selecting 'Complete'.
After the task has been completed there may be additional work you need to do for the task. For example you might want to give it to the testing team to check that it is fixed. You might want to confirm that it has been merged into all the correct versions. After this additional work has been completed you can right-click the task and select 'Close'. This step is optional - it is very common to leave all your tasks as 'Completed'.