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.乌拉：
Wuala 是一种文件同步服务、文件存储服务、文件版本控制服务和备份存储服务，最初由 Caleido Incorporation 提供，但后来归希捷科技所有。它是由Dominik Grolimund和Luzius Meisserin 开发的。它主要是使用Java开发的。它提供了 5 GB 的免费存储空间。它于2008年推出。
iCloud 和 Wuala 的区别：
| ICLOUD | WUALA |
|---|---|
| It is owned by Apple Incorporation. | Originally owned by Caleido Incorporation but was later owned by Seagate Technology. |
| It was launched in 2011. | It was launched in 2008. |
| It offers 5 GB free storage space. | It offered 5 GB free storage space but later on it was made only paid-service. |
| It was developed by Apple. | It was developed by Dominik Grolimund and Luzius Meisserin. |
| It does not provide additional free storage space for referral. | Initially it had referral system but later on referral service was suspended. |
| It has the maximum storage size of 2 TB. | Maximum storage size offered was 2 TB here also. |
| It partly supports file versioning. | It fully supported file versioning. |
| It does not provide ability to trade local disk storage space. | It provided ability to trade local disk storage space against cloud storage. |
| It is still in use. | This service was suspended in 2015. |
| It is mainly used by Apple product users. | It was designed for all types of users. |