I am accessing the Internet, downloading PDFs, and much more, but how?
The servers are far away, but how do I download data if it is far from my computer? I can watch football matches live on television, because of radio & TV waves, but what waves are responsible for Youtube live videos, for example?
Best Answer
Internet signals are mostly transported via cables. Some satellite links exist but they are less common. So we have cables and signals within them. Some cables are made of conducting metals others are glass fibers. The signals in the glass cables do not have the same properties as the ones in the metal wires, they are basically light that is sent through a dedicated path. So then we have the metal cables and signals within them. And indeed signals in metal cables have the same properties as radio waves. Whether the wave in the cable contains digital or analog data does not really matter, cables transport waves and waves are inherently analog. Basically you can model a cable with two endpoints as two antennas that are connected to each other. For an antenna the ground serves as one wire - the mass - and the metal piece pointing into the sky is the other wire. So first you replace the ground with an actual wire and connect the two antennas that way, then you connect the two metal ends that were pointing to the sky, and voila you have a cable. The thing with a cable is that it can transport signals of very low frequency as well as high frequency. Antennas are only suited for high frequency waves, the so called radio waves.