Why does my category not appear in the webshop?

For the category and its belonging products to appear on the webshop, it has to be added to the product menu. 

This is how you do it:

1. In the menu bar, go to "Products" --> "Product Menu". 
2. Search for your category and add it to the product menu.
3. Drag and drop the categories in the order you want it to appear in the webshop.