MOQ stands for Minimum Order Quantity. Some suppliers have a minimum amount of units that you're allowed to order. A supplier may have a product with a 100 unit MOQ, at which case you'd be required to purchase a minimum of 100 units.
MOA is an actual dollar amount, such as a minimum of $1,000 spent with the supplier. This can usually be split up between products, so you could spend $500 on one product, and $500 on another product, in order to meet that MOA.
Is MOQ different than MOA?
What is Minimum Order Quantity and Minimum Order Amount?