Which app is used for video conferencing on Apple devices?

FaceTime is the app specifically designed for video conferencing on Apple devices. It allows users to make video and audio calls over the internet, leveraging Apple's ecosystem to enable seamless communication between iOS and macOS devices. FaceTime supports group calls, making it particularly versatile for virtual meetings or family gatherings. It integrates smoothly with the Contacts app, allowing users to initiate a call directly from their contact list, and it also offers features like Animoji and Memoji for a more engaging interaction.

Considering the other choices, Messages is primarily a text messaging app that supports sending and receiving texts, pictures, and videos, but it doesn't focus specifically on video conferencing. Mail is designed for managing email, while Notes serves as a digital notebook for taking and organizing notes. None of these apps are tailored for video conferencing, highlighting why FaceTime is the clear choice for that purpose.