Imagine you are writing a really important letter to your best friend, but you want to make it look really fancy and special. You can add some extra designs and pictures to make it look pretty, right? Well, that's kind of like what spacing modifier letters do.
Spacing modifier letters are special symbols that you can add to your words or letters to make them look like they have extra little lines or decorations. They don't really change the meaning of the words, but they make them look fancier and more interesting.
For example, let's say you want to write the word "car" with a line above it. You can't just draw a line above the letter "c" because it won't look right. But with a spacing modifier letter, you can add a tiny little line above the "c" that makes it look like it's part of the word.
So, spacing modifier letters are kind of like little decorations that you can add to your words and letters to make them look fancier and more interesting. Pretty cool, huh?