The Minimum Order Quantity (MOQ) requirement specifies the lowest quantity of a certain product that a supplier is willing to sell.
It can be set manually on Vendors -> Vendor Name -> Variants page
It also can be uploaded in a spreadsheet as the part of vendor catalog (Import -> Single Vendor Catalog)
When a MOQ is specified it does not change replenishment numbers for products. However when such product is added to a purchase order and the quantity is below the MOQ it's automatically rounded up to the MOQ number.
The Units of Measurement (UOM) requirement specifies the granularity of products and is used when products are purchased in boxes.
It's also can be set manually on Vendors -> Vendor Name -> Variants page or uploaded as the part of a vendor catalog.
When a product with MOQ is added to a purchase order quantities are automatically converted up to the next MOQ number. E.g. when a MOQ is set to 5 and the replenishment number is 7 it will be converted to 10 (2 packs of 5 items each).