Surface plate

A surface plate is like a big, flat, and super smooth table that people use to make sure things are straight and level. Imagine you have a bunch of people building a very tall tower out of blocks. If everyone just stacked the blocks on top of each other, the tower might start to lean and tip over. That's where the surface plate comes in - it's like a special table that everyone can use to make sure their blocks are perfectly straight and level before they add them to the tower. The surface of the plate is really smooth and shiny, so people can see if there are any bumps or dips in the blocks they're using, and they can adjust them until everything is just right. It's like having a big, flat mirror that helps you see if anything is wonky, so you can fix it and make everything nice and straight.