As with any collection of nodes in maya, you can export assets in your scene as references. File referencing allows you to modularize a parent scene into multiple referenced files so that different people can work on different aspects of it without having to access the parent scene itself. Each time you reload the parent scene, it will reflect the newest versions of the child scenes it references.
Although you can edit a referenced object encapsulated by an asset and save those edits to the referenced file, the real power of assets and referencing comes from the fact that changes to published attributes are stored according to their published names. These reference edits can be saved to an offline file instead of the referenced file.
This means that you can replace references in your scene with assets that have entirely different contents and, so long as the asset names and attributes match the previous asset, your edits will apply to the new asset.
Although you can apply a regular proxy reference to a referenced asset, this greatly reduces your ability to interact with the asset since its published attributes are not available. To remedy this problem you can export a referenced asset as a proxy asset instead.
A proxy asset, like a proxy reference, allows you to substitute a potentially complex referenced asset for a simpler file. Proxy assets are useful for simplifying complex scenes and help to improve navigation or performance when you are primarily concerned with the behavior of components in your scene.
When you create a proxy asset, the proxy file consists of a locator representing the asset’s root node and an additional locator for each parent or child anchor for the asset. You can add additional geometry in the proxy file to better represent the geometry it is being substituted for. Proxy assets retain published attribute values and connections even when reloaded with their proxy files in the main scene. Also, any published parent or child anchors will still appear in the scene’s hierarchy so you can move the encapsulated objects around as needed.