Hey kiddo, have you ever played with a slinky toy? It's a long coiled up spring that can stretch and bounce back. Well, a delay-line oscillator is kind of like a slinky toy, but instead of it being coiled up, it's a long wire that can send signals back and forth.
When we use a delay-line oscillator, we're trying to make something vibrate at a certain frequency. Let's say we want something to vibrate at a frequency of 1000 cycles per second. We can make this happen by sending a signal down the wire, and then waiting for it to bounce back. This bounce-back takes a certain amount of time, and that time is called the "delay" in the delay-line oscillator.
Once the signal bounces back, we can send it down the wire again, and wait for it to bounce back again. The time it takes for the signal to bounce back and forth determines how fast the oscillator vibrates. If we do this fast enough, we can make something, like a guitar string, vibrate at the frequency we want.
So, a delay-line oscillator is basically a long wire that sends signals back and forth to make something vibrate at a specific frequency. It's kind of like a slinky toy, but instead of playing with it, we use it to make music or sound effects. Pretty cool, right?