What is Fifo Lifo in Warehouse Management System ?

FIFO means First in First out and LIFO means Last in First out. Regarding some expiring materials, It's movement should be want fifo basis.such as chemical items, cement etc. First received items should want issue in first before expiring its date. Regarding Last in first out, in some circumstances, immediate expiring items should be want issue first, may be it received in last but don't have the sufficient period to expire than other same materials which stocked in first in WH. Thanks