Arabic (عين) for a determinate property or asset that has a marketable or non-marketable material value that can be converted into other type property or asset (whether cash, tangible or intangible). ‘Ain may include physical commodities whether manufactured or not (examples: copper-made appliances or raw copper), productive or end-user tangible assets (vehicles, machines, etc), or intangible assets (goodwill, business reputation, creditworthiness power, etc).

Generally speaking, ‘ain in the context of Islamic finance transactions, refers to the underlying of a transaction or dealing for which the price or monetary value is paid or exchanged.