There are two types of components accessed by a plugin:

• "Plain-old-data" components, typically implementing Copy. To transfer these to a plugin, the raw struct bytes are copied into the plugin's memory, and the plugin gets a pointer to that data.
• Opaque components, i.e., those not implementing Copy. These typically hold more data. Examples: Inventory of , Window. A plugin accesses these components via host calls without ever getting a copy of the component itself. For example, to get an item from an inventory, a plugin calls quill_entity_get_inventory_item. (The high-level quill API wraps this raw call with an Inventory struct, but the struct doesn't actually hold the inventory. It's just a marker.)