1.投寄箱：
Dropbox是由美国公司Dropbox Incorporation提供的文件托管服务。它提供云存储，文件同步，个人云和客户端软件。它成立于2007年。Dropbox由两名麻省理工学院的学生Drew Houston和Arash Ferdowsi开发。它仅提供2 GB的可用存储空间。它是最早的云存储服务之一。
2. Amazon S3：
Amazon S3代表Amazon Simple Storage Service。它是Amazon Web Services提供的一种云存储服务。它通过Web服务界面提供对象存储。它允许存储任何类型的对象，例如用于分析，数据存档，备份和恢复，灾难恢复，混合云存储和Internet应用程序的数据湖。它由AWS在2006年推出。
Dropbox和Amazon S3之间的区别：
| DROPBOX | AMAZON S3 |
|---|---|
| It is owned by Dropbox Incorporation. | It is owned by Amazon. |
| It was launched in 2007. | It was launched in 2006. |
| It offers 2 GB free storage space. | It does not offer free storage space. |
| It was developed by Drew Houston and Arash Ferdowsi. | It was developed by Amazon Web Services (AWS). |
| It supports less types of file formats. | It supports more types of file formats. |
| It shares files through web applications. | While it shares files through links. |
| It uses block-syncing to update changes quickly. | It does not use block-syncing to update changes quickly. |
| It has the unlimited maximum storage size. | It also has the unlimited maximum storage size for paid users. |
| Maximum file size in Dropbox is 10 GB. | Here maximum file size is 5 GB. |
| It does not require credit-card for free services. | It requires credit-card details for free trial. |