Employee leave can be anything from regular personal time off (PTO) to vacation days, to comp time, maternity leave, military leave, or other types ofpaid and unpaid leave. OrangeHRM gives you the control to define all sorts of leave, actual days off, to assign leave dates, and to define other criteria
relating to your employee leave program.
To manage employee leave:
 Privileged Leave and Casual Leave, http://www.citehr.com/89458-difference-between-casual-leave-privilege-leave.html