Uisng your Mac, iPhone or iPad you can chat with several other Apple users at the same time. You can use this to stay in touch with family and friends while staying at home, as long as everyone involved has Apple products.
If you have iOS 12 and an iPhone X, XS or XR, you can create Memoji characters to add to the existing Animoji characters to use in Messages as animated talking videos. You can design the Memoji using a variety of facial attributes. You can then use these in Messages and also in FaceTime to have a live conversation with the Memoji replacing your actual face.
If you turn on the right options on your iPhone and Mac, you can receive and place phone calls via the FaceTime app on your Mac. These calls can be from or to a non-Apple ID number or even a landline.