Okay kiddo, so imagine you're writing a message from left to right on a sheet of paper, just like you normally would. Now let's say you want to make it a bit harder for someone to read it. One way to do that is to write every other line backwards from right to left, like zig-zagging up and down the page.
That's kind of like what a boustrophedon transform does. It takes a string of letters (also known as text) and flips every other line backwards. So instead of reading it straight across from left to right, you have to follow the ups and downs of the lines to figure out what it says.
This might sound a bit confusing, but the idea behind it is to make the text more resistant to various kinds of attacks. If someone intercepts your message and tries to read it, they'll have a harder time figuring out what it says since they have to read it in a weird, alternating pattern.
Pretty neat, huh? Just remember to practice your writing so you can decipher any boustrophedon messages you come across!