Can I use facetime with internet but no Wi-Fi?

I'm studying abroad this summer in Spain and I know that I will have internet access but we may not have Wi-Fi. If I don't have Wi-Fi, will I still be able to make facetime calls for free over the internet? I'm not really sure what the difference is. I have an iPhone and a Mac as well, so I don't know if it's different over the phone vs computer since I could use both. Do I need Wi-Fi? Or is internet okay?

Internet and Wi-Fi are the same thing. Do you mean Internet and cellular data? If so, which will you have and which won't you.

When your phone is connected to the internet through the cellular network, FaceTime will cost you your data allowance and/or overage fees. FaceTime will be free if your phone is connected to a local Wi-Fi access point.

For your computer, it will cost you if you use the phone's built-in hotspot feature, and will be free if you connect to the local Wi-Fi or wired internet.

You need to connect from your device to a router. You need that router to then connect to the Internet. The first is done either with Wi-Fi or with a network cable. The second is done by buying a service from an ISP. You do need both!