VOA慢速英语--Video Calling Services Compared

（单词翻译）

Video Calling Services Compared

Last week, Google launched Duo, a new video calling app. It was first announced in May this year.

Duo means “two.” As its name suggests, Duo allows two callers to connect on an Android or iOS device.

Duo is easy to use and does not require knowing someone else’s user name. Video calls can be placed simply with phone numbers.

But Duo does require users to download an app.

And it enters a crowded field of video calling services, including Skype, FaceTime, Messenger and Hangouts.

Choosing a service

Choosing a video calling service can be difficult because the services have different features. The key is learning what features are important for what situations.

Some people use more than one video calling service. For example, they may use one service with friends and another for business.

Fortunately, all these services are free, so users can try them without spending any money.

Here are some things to consider when choosing a service:

1) Adding an app

Many of these services do not work unless you download a separate app for them. If your friends don't already have a video calling app, they may be unwilling¹ or unable to download a new one.

2) Signing up for an account

Similarly, if you don't want to sign up for a new account to use a video chat service, you may want one that works without needing a new account.

For example, FaceTime is built into Mac computers, iPhones and iPads. No additional app is necessary.

And because many people already are on Facebook, they can use Messenger for video calls without downloading a new app.

3) Voice calls

Some services also offer voice calls.

For example, FaceTime, Messenger and Skype allow users to make voice as well as video calls.

Skype offers voice calls to other Skype accounts for free and to phone numbers for a fee.

FaceTime lets users call iPhone phone numbers around the world for free.

4) Platforms

The more platforms a video calling service can work on the better. Duo, Skype, Messenger and Hangouts all offer apps across platforms. They can be used on both Android and iOS devices, such as iPhone and iPad.

FaceTime is for Apple devices only –including Mac, iPhone and iPad.

5) Computer

Many video calling services can be used on computers as well as on mobile devices.

FaceTime, Messenger, Skype and Hangouts all let users make video calls using a computer, phone and tablet. Users do need to have a video camera on their computers to use these services.

Duo is not available for computers.

6) Ease of use

Duo and FaceTime are the easiest services to use. Calls can easily be answered, and users can switch between the front and rear cameras on a phone.

7) Connecting with others

Connecting with others should be simple.

Skype users must know a friend's user name before placing a video call on Skype.

But Duo and FaceTime users need only a friend's phone number to place a video call.

Messenger lets users make video calls to their Facebook friends.

And Hangouts users can place calls with their friends’ Gmail addresses or on Google Plus.

8) Multiple users

Some video calling services let users have group chats with multiple people joining the call at the same time.

Hangouts, Skype and Messenger let users add multiple people to the call.

Duo and FaceTime allow users to connect only two callers.

9) Screen sharing

Screen sharing allows users to display their computer screens in the video call instead of the image from the camera. This feature is useful to demonstrate something or to get help solving a computer issue.

Hangouts and Skype allow screen sharing.

Comparing services

This chart sets out the different features for each service. (Double click or tap on the chart for a larger view.)

Duo

Duo is available as an app on:

Duo has a feature called Knock Knock that shows video from the caller before the user answers the call. Knock Knock works only on iOS when the Duo app is open.

The app will also lower the quality of the video if the Internet signal strength is weak.

Because Duo is new this month, users will probably have to ask friends to add the app in order to connect with the service.

FaceTime

FaceTime lets users of Apple products connect via video and voice calls.

The service is easy to use and available on iPhone, iPad and Mac computers. Users can connect with others using cell phone numbers or email addresses.

Skype

Skype is Microsoft's video chat service. Users can also make voice calls on Skype.

Skype calls can be made using a computer or mobile device. People then use screen sharing to see each other’s screens during a video call.

Up to 25 people can be added to a group Skype call.

Skype also offers voice messages and other features.

Messenger

Facebook's video calling service, Messenger, is available on computers in chat using Chrome, Firefox and Opera browsers³, but not on Safari⁴.

It also works on mobile devices in the Messenger app.

Users click on the camera icon⁵ to begin a video chat with a Facebook friend.

In April, Messenger was updated to allow group chats.

Hangouts

Google's other video calling service is Hangouts, which is available on computers and mobile devices using the Hangouts app. Users can add multiple people to the video chat and share their computer screens.

Words in This Story

download - v. to move or copy (a file, program, etc.) from a usually larger computer system to another computer or device

platform - n. a program or set of programs that controls the way a computer works and runs other programs

browser² - n. a computer program that is used to find and look at information on the Internet