# Packages

Packages are physical packs or boxes stored in a stock location with specific sizes and ready for shipment. Each stock location in a market can have its own set of defined packages with a pre-defined package `length`, `weight`, and `height`. That information about the package dimensions — required for the package creation — is used by [shipping carriers](https://docs.commercelayer.io/core-api-reference/carrier_accounts) to calculate shipping rates.

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<summary>Data model</summary>

Check the related [ER diagram](https://commercelayer.io/docs/data-model/parcels-and-packages) and explore the flowchart that illustrates how the package resource relates to the other API entities.

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