Microsoft NetMeeting was a program that people could use to talk to each other over the internet. It was like a phone call, but instead of just talking, you could also see the person you were talking to on your computer screen.
It was used a lot when people didn't have smartphones or video call apps like FaceTime or Skype.
However, NetMeeting is an old program and isn't used much anymore. Nowadays, people use other programs and apps that are better and have more features.