1. 谷歌语音：
Google Voice 是一种电话服务，提供呼叫转移服务和语音邮件服务。它允许用户拥有一个号码并将其转发到多部电话。它由 Google 于 2009 年推出。它适用于 web、android 和 iOS 系统。尽管更改了电话设备，它仍然可以保留电话号码。它使用用户的 Gmail 中的联系人。它提供许多服务，例如语音邮件、免费短信、通话记录、呼叫筛选、阻止不需要的电话以及语音转录到语音邮件消息的文本。
2. 谷歌二重奏：
Google Duo 是一款适用于 Android 和 iOS 操作系统的视频通话移动应用程序。它也可以通过个人计算机上的 Chrome 网络浏览器使用。它使用户能够获得高质量的视频通话服务。它以这样一种方式开发，即使 id 用户的互联网服务速度很慢，它也能正常工作。端到端加密可实现高安全性。它还支持群组视频通话。早些时候它的组大小为 8，但后来扩展到 12。它由 Google LLC 推出。它于2016年推出。
Google Voice 和 Google Duo 的区别：
| GOOGLE VOICE | GOOGLE DUO |
|---|---|
| It is a telephone service that provides call forwarding and voicemail services. | It is a video chat application that provides video calling services. |
| It was launched in 2009. | It was launched in 2016. |
| It offers messaging and voice calls. | It offers messaging, voice calls and video calls. |
| It offers text messaging. | It recently added service for recorded messaging but does not offer text messaging. |
| It is mainly used for making voice calls. | It is mainly used for making video calls. |
| It does not require to have gmail signing. | It requires to have gmail signing. |
| It provides services like call forwarding and voicemail. | It does not provide such services. |
| It has less number of users. | It has comparatively more number of users. |
| It does not provide services for group creation. | It provides services for group creation. |
| Only 2 people can be involved in calls. | Up to 12 people can be involved in calls. |