The term "television" was coined in the early 20th century, when the technology was still in its infancy. At the time, radio was a well-established technology, and many people believed that television would simply be an extension of radio. As a result, the "R" in TV was used to denote the connection between the two technologies.
Over time, the meaning of the "R" in TV has evolved. Today, it is more commonly understood to stand for "receiver." A television receiver is a device that receives and decodes television signals and displays them on a screen.
The "R" in TV can also be used to refer to the "resolution" of a television. Resolution is a measure of the number of pixels that make up a television image. The higher the resolution, the sharper and more detailed the image will be.