Okay kiddo, so you know how some things need a little boost to make them stronger? Well, a fet amplifier does just that for electric signals.
A fet is short for "field-effect transistor," which is like a tiny switch that can control the flow of electricity. When the electricity flows through the fet, it's like a water faucet turning on or off.
Now, an amplifier takes a weak signal and makes it stronger. So, when you put a weak electric signal through a fet amplifier, the fet acts like a super tiny faucet and makes the signal stronger.
Think of it like adding soap to water to make bubbles. The soap makes the water stronger and the fet amplifier makes the signal stronger.
So fet amplifiers are useful when you need to boost weak signals, like in music systems or communication devices. And that's a fet amplifier, in a nutshell!