required clarity about Maint. notification and order

Hello Experts,

Please let me know on below points for more clarity about the functionality.

1. Maintenance Notification ?

i.     What are the advantage and disadvantage to creation of different type of notificatoins

ii.     Why notification need to be created why not directly create maintenance order ?

iii.     If a small work need to be done then should be create a notification for that ?

iv.     What benifities will be getting from creation of notification ?

v.     What are the reports availability for maintenance notification ?

2. Maintenance order.

i,     What are advantage and disadvantage for creation of maint. order why its rquired.

ii.      what are the benifities for creation maint. order ?   

iii.     can we directly create a maintenance order without any reference with notification,

iv. what are other functionlity will get from maint. order ?

These are my queries comes in my mind, for basic functionlity i know but need details funcitonality

please give some more clarity for both of call object

thanks

PK