Okay kiddo, do you know how sometimes you type things on the computer and they look weird or have funky symbols? That's because the computer uses something called "encoding" to understand what letters and symbols you're trying to use.
One popular type of encoding is called UTF-8, which is like a special language the computer uses to read and write symbols from different languages (like Chinese, Arabic, or Spanish).
Now, UTF-16 is another type of encoding that computer people use to read and write symbols, but it's like a slightly different version of UTF-8. Instead of using 8 bits for each symbol (like UTF-8), it uses 16 bits.
Why would someone want to use UTF-16 instead of UTF-8, you ask? Well, it's mostly because some languages have symbols that need more space to be "encoded" properly (like some fancy math symbols or ancient scripts). So, UTF-16 can help make sure all those symbols show up correctly on your computer screen.
But don't worry too much about it for now, kiddo. As long as you type in English or another common language, you probably won't even notice which encoding your computer is using!