If you have products that are limited in quantity and you wish to ensure customers only buy a limited quantity this can be done on either a store wide basis or per product.
Site Settings > Retail Settings
Ochre holds stock for customers whilst they have it in their carts meaning they are guaranteed their purchase once they have it in their cart. This can have unintended consequences if customers hold large quantities in their cart meaning that the product will go out of stock for other customers. If you find this happening you can set the store level purchase limit to a suitable threshold to ensure this does not happen.