> For the complete documentation index, see [llms.txt](https://readme.directual.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://readme.directual.com/data/data-structures/system-structures.md).

# System Structures

Each app starts with several **system structures**:

![](/files/-M5HQveTWoxtgTKFaXiV)

### Frequently used system structures:

| Folder              | Structure name           | Structure system name | What is it for?                                                                                                                      |
| ------------------- | ------------------------ | --------------------- | ------------------------------------------------------------------------------------------------------------------------------------ |
| Root/               | **App users**            | `WebUser`             | Objects are your app users. [RBAC is based](broken://pages/-M4ORivK1hGzFJTL3NfZ) on the properties of the objects from **App users** |
| Root/               | **Files**                | `FileUpload`          | [File storage](/data/file-storage.md)                                                                                                |
| Root/ System/       | **App global constants** | `GlobalVariables`     | Data structure for storing[ global constants](/scenarios/using-variables/global-constants.md)                                        |
| Root/ Integrations/ | —                        | —                     | Contains data structures for your [integrations](https://www.directual.com/integrations)                                             |

### Less frequently used system structures:

| Folder              | Structure name       | Structure system name | What is it for?                                                                |
| ------------------- | -------------------- | --------------------- | ------------------------------------------------------------------------------ |
| Root/ System/       | **User sessions**    | `WebUserSession`      | Store sessions for **App users**                                               |
| Root/ System/       | **Social sessions**  | `SocialUser`          | Store connection to social accounts (Facebook, Google, etc.) for **App users** |
| Root/ System/ Logs/ | —                    | —                     | Store app logs, which you can see on the Dashboard                             |
| Root/ System/ Logs/ | **Import data logs** | `ImportInformation`   | Data import operation status for objects                                       |