FaceTime and iChat are two different apps. FaceTime will do Video only and tow one person at a time. This person can be on an iPhone (4), certain iPod Touches with an Apple ID rather thana phone number or another Mac with Face time on it. FaceTime comes in Lion. In Snow Leopard it was downloadable from the App Store. To have a FaceTime call with one other person, you need a Mac with OS X Lion 10.7 or later, a broadband Internet connection, and a built-in or connected microphone or camera. Or use your iPhone, iPad, or iPod touch. To call a group of people, follow the steps in Use Group FaceTime on Mac. 12 Remove your iMessage and FaceTime keys in Mac’s Keychain; 13 Delete your Mac’s Push Notification for iMessage and FaceTime. 13.1 Look in your Mac’s main Library folder, not your user library; 13.2 Check the last time your APSD file updated; 13.3 Remove Your Mac’s aspd.plist; 14 Check if Apple Placed a Block on iMessages or FaceTime. Apple has released a bug fix for FaceTime that resolves an issue that could prevent Snow Leopard users from connecting to FaceTime calls. 9to5Mac: Of course, if you’re on anything newer than Snow Leopard, you don’t need this update, but anyone still running OS X 10.6 who already purchased the app can get the free update to resolve the problem.
For those of you still hanging in there with Snow Leopard, there’s a bit of update goodness from Apple that is now available to you. Apple has released a bug fix for FaceTime that resolves an issue that could prevent Snow Leopard users from connecting to FaceTime calls.
9to5Mac:
Of course, if you’re on anything newer than Snow Leopard, you don’t need this update, but anyone still running OS X 10.6 who already purchased the app can get the free update to resolve the problem.
The update is available via the update tab in the Mac App Store. And if you haven’t installed FaceTime on your Snow Leopard machine, it’ll cost ya’ $0.99 in the Mac App Store.
To have a FaceTime call with one other person, you need a Mac with OS X Lion 10.7 or later, a broadband Internet connection, and a built-in or connected microphone or camera. Or use your iPhone, iPad, or iPod touch.
To call a group of people, follow the steps in Use Group FaceTime on Mac.
The person you're calling doesn't need to have the FaceTime app open, but to receive the call on their Mac, iPhone, iPad, or iPod touch, they do need to be signed in to FaceTime on that device. You can then call them using any phone number or email address they set up for FaceTime.
Open the FaceTime app and enter the email address or phone number of the person that you want to call. If the person is in your Contacts app, you can enter just their name. Then click the Audio button or Video button to call.
You can also just ask Siri to ”FaceTime John” or ”FaceTime audio Lisa,” for example.
From the notification that appears on your Mac, click Accept to answer the call in the FaceTime app.
If you click the arrow next to Accept, you can choose to accept as an audio call instead of video call. If you click the arrow next to Decline, you can choose to send a message to the caller or set a reminder to call back later.
You can also use the Touch Bar to accept or decline a FaceTime call.
Anyone on the call can add more people to the call, creating a Group FaceTime call.
Lean more about how to use Group FaceTime.
During a call, move your pointer over the FaceTime window to show these controls.
Mute Video
Turn the video from your camera off or on.
Full Screen
Switch to or from a full-screen FaceTime window.
Camera Shutter
Take a Live Photo of the other person.
FaceTime is not available in all countries or regions.