Well, little one, if you have ever seen a music band play, you might have noticed that the sound they produce is not just one single note, it is actually a combination of different notes that together make a melody.
Similarly, in physics, an oscillator is a device that produces a sound at a certain frequency or wavelength. However, just like a music band, the sound produced by an oscillator is not just one single frequency, it contains a range of frequencies. This range is called the linewidth of the oscillator.
Now, let's imagine you are playing a game of catch with a friend. If you throw the ball very precisely and accurately, your friend will be able to catch it with ease. However, if you throw it in a wide range of directions, your friend might have a hard time catching it.
Similarly, the linewidth of an oscillator tells us how accurate and precise the frequency of the sound produced is. A large linewidth means the oscillator produces a wide range of frequencies, making it less accurate and precise. A small linewidth means the oscillator produces a narrow range of frequencies, making it more accurate and precise.
In conclusion, linewidth is the range of frequencies produced by an oscillator and it determines how accurate and precise the frequency of the sound produced is.