When you assign a task to more than one person, you will be presented with a new option.
Assign Individually
When you assign the task individually, two independent tasks will be created for each person.
As the creator of the task, you will be able to comment on each task separately without assignees seeing your comments.
This task type can be used in scenarios where you want each employee to complete the same task - such as revising the quarterly forecast.
Assign as a group task
When you assign the task as a group task, only one task will be created and the task status will be common for all assignees.
Whenever someone marks the task as completed, the task will be completed for all assignees. Comments left to the task will be accessible to all assignees of the tasks.
This task type can be a good example for group projects where all members work together to accomplish a common task.