Riba (sudxo'rlik) — bu bir turdagi mol-mulkni xuddi shu turdagi boshqa mol-mulkka teng bo'lmagan miqdorda olish amaliyotidir. Sarf (pul ayirboshlash) — oltin va kumushdan bo'lgan bir xil turdagi mol-mulkni yoki ikki xil turdagi mol-mulkni teng miqdorda yoki afzallik bilan olish amaliyotidir. Ayirboshlash faqat savdoda bo'lishi mumkin, sudxo'rlikka kelsak, u faqat sotuv-sotib olish (Bay') bitimida, qarz (Qardh) yoki Salam (oldindan sotib olish) shaklida bo'lishi mumkin. Savdo (Al-Bay'u) — mol-mulkni mol-mulkka almashtirish orqali mulk almashinuviga olib keladigan amaliyotdir; bu Alloh (SWT) aytganidek ruxsat etilgandir:

Riba (usury) is the practice of taking property for another property of the same type unequally. The money exchange (Sarf) is the practice of taking a property for another property from gold and silver of the same type equally, or of two different types equally or preferentially. The exchange can only take place in trade, as for usury, it can only happen in a trade (Bay’u) transaction, in a loan (Qardh) or in a Salam (forward buying). Trading (Al-Bay’u) is the practice of exchanging property for property resulting in an exchange of property; this is permitted for Allah (swt) says: