# Shipments and shipping categories
{% hint style="info" icon="lightbulb" %} A shipment groups one or more parcels for delivery to a customer's address. The inventory strategy controls how many shipments an order generates. Shipping categories can further split an order when items require different delivery methods. {% endhint %} ## Shipments A [shipment](/core-api-reference/shipments.md) is a group of one or more parcels ready to be shipped to a customer's address. Every order is associated with two [addresses](/core-api-reference/addresses.md): * **Origin address** (FROM) — the stock location or warehouse the items ship from. * **Shipping address** (TO) — the customer's destination. The [inventory strategy](/how-tos/inventory/strategies.md) determines whether and how an order is split and how many shipments are created. The default strategy is **no split**, which always produces a single shipment from a single stock location. With a different strategy, orders can be split into multiple shipments when: * Items come from more than one stock location. * Items belong to more than one shipping category. All necessary resources are automatically generated based on the chosen strategy. If needed, you can still manually create, modify, or delete shipments after the order has been approved. You can integrate any fulfillment service and provide real-time tracking updates to customers from the associated carrier account. ## Stock line items [Stock line items](/core-api-reference/stock_line_items.md) are the SKUs in an order distributed across one or more shipments. When an order is not split, all SKUs belong to a single stock line item. When split, line items are distributed across multiple shipments. A single line item can also be split into more than one stock line item. You can create new stock line items or modify existing ones as long as the chosen quantity is available in one of the market's inventory stock locations. You can also add stock line items for products not originally part of the order — for example, to include a free gift or replace an unavailable item. ## Shipping categories [Shipping categories](/core-api-reference/shipping_categories.md) are one of the reasons an order can be split into multiple shipments. Unless the **no split** strategy is in use, orders containing items from two or more shipping categories are split into one shipment per category. A shipping category lets you define the specific shipping methods available for its associated SKUs. The category and the shipping zone an item belongs to together determine the delivery options shown to customers before shipment. Association with a shipping category is mandatory for all SKUs, except those marked as **do not ship**. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.commercelayer.io/data-model/shipping/shipments-and-shipping-categories.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.