The most straightforward answer is that a radio is a device that emits or receives radio waves. You may already know that radio waves belong to the wider category of electromagnetic waves, which also includes light, x-rays, and even gamma rays. These waves can travel through a variety of materials, including air, wood, glass, and concrete, as well as the empty vacuum of space. They actually like to travel across empty space. Some waves, such as light, x-rays, and gamma rays, can flow through varied amounts of water or metal with relative ease. The radio waves we're interested in don't penetrate water very effectively, and they're only stopped by a small quantity of metal.
If a radio's main function was to generate or respond to radio waves, it would be a fascinating scientific curiosity, but perhaps not much more. Radio's ability to facilitate communication is what makes it so important in today's culture. Make a list of as many distinct ways that one person can communicate with another person as you can. How many of those methods necessitate the two people being in close proximity to one another? When it comes to certain types of communication, can people be separated by a significant distance? Which happens right away, and which takes hours, days, or even weeks? Which ones require the use of a wire to connect the people's locations?
A radio transmitter (also known as a transmitter) is a device that can turn some type of information (such as voice, music, or computer data) into radio waves that can travel through the air or space without the use of wires. An antenna transmits the waves into space. A radio receiver (commonly referred to simply as a receiver) intercepts radio waves from the air or space (using its own antenna) and converts them into the information that people require. The radio waves are not "used up" by the receiver; in fact, a single transmitter can emit radio waves that can be "listened" to by a large number of receivers.
People soon began to wonder how lovely it would be if a relatively recent innovation known as the telephone could be made to work without wires as well. The radiotelephone was developed quickly by scientists and engineers. They rapidly realized that more than one person could listen at the same time, and they began transmitting. The commercial was invented not long after, and modern civilization has never been the same since.
Wouldn't it be fantastic if moving visuals could be broadcast over the air, allowing a large number of people to view the same movie at the same time without having to leave their homes? Say hello to television, which is simply another form of radio. Now, instead of plucking television images from the air with an antenna as in "the good old days," most of us receive television images over a wire (cable). But how many of you have seen a TV dish that picks up satellite television signals? The dish is just an antenna that is attached to a special type of radio receiver that reconstructs the images and sounds.
So now you know how radio works, you should try reading about internet radio stations as the next step of radio evolution in its history.
