Task Assignee is a user who is assigned to work on task. Task can have only one Task Assignee.
User becomes Task Assignee in 2 cases:
she is one of multiple assignment candidates for the task and assigns task to herself
she is a single candidate assignee and is automatically assigned to work on the task
As soon as you become Task Assignee, you can view it in "My tasks" list on Tasks screen ("Active" tasks filter should be used) and can start working on task. The main goal of Task Assignee is to complete the task.
Task Assignee may do the following:
View task details
View and edit task data form, fill in required form fields
Write comments about the task to other users
View task history
Change task due date
Complete the task
Reopen the task completed by self
If something goes wrong Task Assignee can unassign the task from herself, which allows other assignment candidates to take this task.
As soon as task is completed it moves from "My tasks" "Active" list to "Completed" list on Tasks screen.
During the work on task, assignee receives email notifications related to task changes (new comments, task status changed to "done" by process manager, etc.)