We've mentioned the usage of Product Tags already in Chapter 2, Creating Your First Products. Using tags works exactly in the same way you're used to while writing WordPress posts. So here, we do not want to spend too much time explaining the concept.
Just be aware that Product Tags and Tags for Posts are actually separated from each other. You may find the tags that you already used by navigating to Products | Tags in the menu on the left of your screen. Note that the tags you entered during product creation appear here. Besides, it's also possible to create a list of tags immediately in the Edit Product screen and use them later on. Tags are a great addition for your store, but don't overdo it! Having multiple tags delivering the same result will lead to duplicate content issues and harm your rankings in the search engines.