What is the difference between ghanimah (spoils of war) and fay'?

The difference between ghanīmah (spoils of war) and fayʾ (booty) is that ghanīmah is what Muslims seize from the enemy's wealth through force and combat. It is then divided among the fighters after deducting one-fifth for the Muslim treasury (Bayt al-Māl), as stated in His Almighty's saying: "And know that whatever thing you gain, a fifth of it is for Allah and for the Messenger and for [his] near relatives and the orphans, the needy and the traveler." As for fayʾ, it is what Muslims obtain from wealth without fighting. Its allocation is to the treasury and is subject to the discretion of the ruler, as stated in His Almighty's saying: "What Allah has returned to His Messenger from the people of the towns - it is for Allah and for the Messenger and for [his] near relatives and the orphans, the needy and the traveler - so that it will not be a perpetual distribution among the rich from among you."