A wythe is a fancy word for a layer or a row of bricks that are built up to create a wall. It's kind of like building with Legos, but with bricks instead. You stack one layer on top of the other until you have a wall that is strong and sturdy. A wythe can be made up of different types of bricks, like big ones or small ones, depending on what you want your wall to look like. It's important to make sure each wythe is level and straight so that your wall won't fall down. So, think of it like building a big puzzle out of bricks, one piece at a time, until you have a wall to keep you safe and warm.