Wirth syntax notation is a way to show how a computer program should be written. It's like when someone writes a recipe to bake a cake so that you know what ingredients to use and in what order to mix them.
In Wirth syntax notation, different parts of the program are shown with different symbols. For example, a line of code might start with a word like "if" to show that it's a condition, or it might have a symbol like "{" to show that it's the start of a block of code.
It's important to write programs correctly so that they work the way they're supposed to. Wirth syntax notation helps make sure that everyone is following the same rules, like when everyone follows the same recipe to bake a cake.