A product property is a product field which is only shown on a product if it has a value or is explicitly added. Technically, a product property is a product category field with a special property (Hide if empty) set to true. Read about creating product properties here.
Product properties can be added, removed, and sorted manually by clicking the Add property button and launching the hidden fields dialog (Figure 1.1).
Using this dialog you select which properties should be included on this particular product. You do so by moving them from the hidden fields column to the included fields column. The sort order of the included fields column will be reflected in frontend.
You should be aware that using product properties may result in a significant performance hit – we recommend that you explore other options such as regularizing or structuring the secondary product data so that regular product categories may be used instead.