An item is a UPC (barcode) in Mochila's system that uniquely identifies an item of inventory. The best way to think about an item is to think about the barcode that identifies which item should be sent to a customer to fulfill their order. The item identifies those units of inventory that could be used to fulfill a customer's order.
For example, let's say you sell a navy shirt. You may identify this navy shirt with a SKU, NAV-SHT-123. In addition, you may sell this shirt in different sizes: Small, Medium, Large, X-Large. In this example, each size of this SKU would be its own individual item with its own UPC or barcode. The table below explains how this SKU with the 4 different sizes (4 different UPCs) might be set up in Mochila's system:
| SKU | UPC | Item Name |
| NAV-SHT-123 | 012301234506 | Navy Shirt, Size Small |
| NAV-SHT-123 | 012301234507 | Navy Shirt, Size Medium |
| NAV-SHT-123 | 012301234508 | Navy Shirt, Size Large |
| NAV-SHT-123 | 012301234509 | Navy Shirt, Size X-Large |
You'll note, from this example, that multiple UPCs can be associated with a single SKU. You should also note that the UPC code must be unique. This is because the UPC is the barcode on the product that ensures Mochila ships the right product to your customers.
In other words, if you had the same UPC code for two different sizes, then Mochila might send the right SKU, but the wrong size, to one of your customers.