Applying custom information to specific products in point of sale order
When building your field you can assign the field to apply to orders or line items. Fields that apply to line items will be applied to each line item as a line item property.
Line item fields are ideal for applying data to specific products in the cart - for example engraving options. Once the order is completed, the value will be stored as a line item property, which can't be edited in the Shopify admin without using the Shopify admin API or an app.