Telepresence was a technology that allowed a person to feel as if he/she or someone else was present at a place other than their actual location. When telepresence entered the mainstream, it took over the world of telecommunications.
Teleconferencing was a concept that allowed visual communication over long distances. It entered the mainstream with the launch of Skype in 2003. People could communicate visually from anywhere on the planet. As time went on, the Internet was incorporated into television. With OLEDs, wall screens were created that allowed people to communicate over long distances when their were scheduling conflicts. Many people were starting to feel as if the person they were talking to was there when in fact, the person wasn't.
Tech Level: 10
As mentioned above, telepresence was in the early 21st century becoming commonplace. However, it would not enter the mainstream until the virtual retinal display entered the mainstream, too. One of the features of this new technology was that it could create holographic images. Companies specializing in virtual retinal displays found a way to exploit this property by allowing people when they want to make a phone call to create a holographic image of the person they want to call. The people on the phone call would often feel like they were in the same place. This was telepresence. Implantable brain-computer interfaces actually allowed people to touch the holographic images of their friends strengthening the illusion. Eventually, telepresence would allow people to feel like they had new bodies.