# Drive overview
This document introduces the definition of resources in drive, interface usage restrictions, capability access process, and more.
## Basic concepts
The resources contained in drive and their definitions are as follows. The Feishu Open Platform has opened a series of interfaces based on the following resources.
- **Drive**: A container used to manage all cloud document resources.
- **Folder**: A container used to manage files and other folders. For details, refer to [Folder Overview](https://open.feishu.cn/document/ukTMukTMukTM/ugTNzUjL4UzM14CO1MTN/folder-overview).
- **File**: A general term for various types of files, generally referring to all files in drive. This includes online documents, spreadsheets, Base, Mindnotes, documents in the knowledge base created in drive, as well as various files uploaded from the local environment. For details, refer to [File Overview](https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/reference/drive-v1/file/file-overview).
- **Media**: Resource materials used in documents, spreadsheets, Base, etc., such as images, videos, or files in documents. For details, refer to [Media Overview](https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/reference/drive-v1/media/introduction).
- **Version**: A version is a version generated based on a file. Versions exist as attachments to files. Currently, the Feishu Open Platform supports creating, deleting, and viewing versions based on online documents and spreadsheets. For details, refer to [Version Overview](https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/reference/drive-v1/file-version/overview).
- **Event**: Various events triggered when the content of files and folders changes. For details, refer to [Subscribe to Cloud Document Events](https://open.feishu.cn/document/uAjLw4CM/ukTMukTMukTM/reference/drive-v1/file/subscribe).
- **Node**: In drive, a node is the basic unit for managing and organizing resources. A node can be a folder or a file which can be mounted directly in the drive. Each node represents a specific resource or container.
The relationship between various resources in drive is shown in the figure below:
## Limitations
- The upper limit of nodes in the root directory or a single layer of folders in drive is 1500. When this limit is exceeded, the interface will return error code 1062507. You can resolve this by creating new files in different folders.
- The upper limit for the total number of nodes in all levels of drive is 400,000.
- The following interfaces related to modifying node states or changing node structures in drive do not support concurrent calls, and the call frequency limit is 5 QPS, 10,000 times/day. Otherwise, error code 1061045 will be returned, and you can resolve this by retrying later.
Category | Interface
---|---
Folder-related interfaces | - Create folder
- Move or delete folder
File-related interfaces | - Create file
- Copy file
- Move file or folder
- Delete file or folder
- Create file shortcut
- Upload file
- Shard upload file - Pre-upload
- Shard upload file - Upload shard
- Shard upload file - Complete upload
- Download file
## Access process
The process for accessing Drive OpenAPI is shown in the figure below. For more information, refer to the **How to integrate** section of [Cloud Document Overview](https://open.feishu.cn/document/ukTMukTMukTM/uUDN04SN0QjL1QDN/docs-overview).
