You can use FaceTime if you have a newer Mac, iPhone 4Gs, iPod Touch that has a built-in camera, and so forth. That's if you want to talk with your family members as you look at each other. FaceTime uses Wi-Fi. For example, with a Mac at work using the Wi-Fi there, while your family members using another Mac, or an iPhone 4Gs, or a late generation iPod Touch, iPad, etc. and the Wi-Fi at home.
How to Use FaceTime For Mac to Chat with Friends & Family
That said, a lot of people prefer Skype, maybe because it has been around for a long time and people have gotten used to it.