A leave of absence is a period of time that one must be away from one's primary job, while maintaining the status of employee.
MEDICAL LEAVE OF ABSENCE - Bastien Salabanzi by The Berrics
This contrasts with normal periods away from the workplace, such as vacations, holidays, hiatuses, sabbaticals, and "working from home" programs, in that they are considered exceptional circumstances, rather than benefits.
A holiday is a day set aside by custom or by law on which normal activities, especially business or work, are suspended or reduced.
Sabbatical or a sabbatical is a rest from work, or a break, often lasting from two months to a year.
Generally such an arrangement has a predefined termination at a particular date or after a certain event has occurred.