1. 云：
iCloud 是苹果公司提供的云存储和云计算服务。它允许用户将文档、照片和音乐等数据存储在远程服务器上，以便下载到 iOS、macOS 或 Windows 设备。它还能够与其他用户共享和发送数据。如果 Apple 设备丢失或被盗，管理它也很有帮助。它于2011年推出。
2.亚马逊S3：
Amazon S3 代表 Amazon Simple Storage Service。它是由 Amazon Web Services 提供的云存储服务。它通过 Web 服务接口提供对象存储。它允许存储任何类型的对象，例如用于分析、数据归档、备份和恢复、灾难恢复、混合云存储和互联网应用程序的数据湖。它由 AWS 于 2006 年推出。
iCloud 和 Amazon S3 的区别：
| ICLOUD | AMAZON S3 |
|---|---|
| It is owned by Apple Incorporation. | It is owned by Amazon. |
| It was launched in 2011. | It was launched in 2006. |
| It offers 5 GB free storage space. | It does not offer free storage space. |
| It was developed by Apple. | It was developed by Amazon Web Services (AWS). |
| OneDrive is mostly used by professionals. | It is used for both professional and personal works. |
| It is mostly used by Apple device users. | It is used by users using any internet devices. |
| It has the maximum storage size of 2 TB. | It has the unlimited maximum storage size for paid users. |
| It does not support remote uploading. | It also does not support remote uploading. |
| Maximum file size in iCloud is 50 GB. | Here maximum file size is 5 GB. |
| It supports file versioning but partially. | It fully supports file versioning. |
| It does not require credit-card for free services. | It requires credit-card details for free trial. |