Is it possible to log time sheet on 'Execution' tasks in Project Management?

Summary:

We have assigned a resource to a 'Project Management' project task which is an 'Execution' task only. This resource has the following check box checked, 'Track Time'.

Question is how is 'Track Time' used and is it possible to capture time sheet which generates actual costs using the organization costing rules?

How is this helpful in financial project management?

Thanks.

Atul