Mass Allocation / Auto Allocation

 Hello,

What is the difference between following three in Oracle GL  r12?  Are they very separate entities from each other or component of Allocation setup as a whole?

1. Mass Allocation  (Standard Navigation Path:  Journals>>Define>>Allocation)

2. Auto Allocation ( Standard Navigation Path:   Journals >> AutoAllocation:Workbench)

3. Allocation ( Standard Navigation Path:   Journals >> Generate>> Allocation)

At our site, we do not use any allocation whatsoever. But we are planning to use allocation to allocate a fixed cost to various departments/cost centers.  And, I am stuck with too many choices mentioned above.

Please help.

Thanks,

R