Scottish units are a way of measuring things in Scotland a long time ago. There were different types of Scottish units for measuring length, weight, and volume.
For measuring length, people used "feet" which is just like measuring how many steps you take from one place to another. But in Scotland, they used a different size for a foot than other places did. They also used "ells" which is like a long arm from your elbow to your fingertips, to measure longer lengths like fabric.
For weighing things, they used "stones" which is like a big rock. They also used "pounds" which is like a heavy object that you can hold in your hand. The Scottish pound was actually different from the pound used in England and other places.
For measuring volume, they used "gallons" which is like a big bucket. But again, the Scottish gallon was a different size from the gallon used in other places.
Today, Scotland mostly uses the same units as the rest of the UK and other countries. But some people like to use the traditional Scottish units to keep old traditions and history alive.