Asset Storage API
You may think of the Asset Storage API as an abstraction of a file system. The assets (such as designs, fonts, images, etc.) are similar to files, they can be organized in folders, you can perform the CRUD operations on them.
In practice, you rarely create files directly with this API. The reason is that you usually need more than a file: you also need its metadata and a preview image. To upload anything to the storage, use the import operation of the Asset Processor API.