Allocation request: It is the number of days (per leave type) that you (the employer) are allocating to an employee (or a category of employees) for a certain period. For example, if regular employees are supposed to have 15 paid vacation days per year, 10 paid sick days per year, and an unlimited number of unpaid vacation days per year (after having used up their paid ones), you will have to create one category of employees (regular employees), 3 leave types (paid vacation days, paid sick days, unpaid vacation days), and the 3 allocations will be:

• 15 paid vacation days per year for all regular employees
• 10 paid sick days per year for all regular employees
• unlimited number of unpaid vacation days per year for all regular employees

It is called an allocation request because because you could be in a situation where the employees are supposed to request these to their management. More generally, it would be the HR department who would set that up once and for all at the beginning of the fiscal year and at the beginning of each employment (as part of an onboarding procedure) rather than the employee himself requesting allocations.

Leave request: This is what an employee will create to ask his manager to be off on a certain date, whatever the reason (federal holidays, paid sick day, wedding, funeral,...). The manager will then accept or reject this request. The leave can only be requested by the employee if a corresponding allocation exists for him. For example, if he has used all his paid vacation days, he will not be able to make a request with this leave type.

As a summary: The management gives the right (=allocation) to an employee to request certain types of time-off (=leaves).