When trading at eBay, the more informed you are regarding an item, the better. Third-party expertise, such as grading, authentication, verification and appraisal services can provide a second opinion on an item. These services provide another source of information to help you evaluate an item and make your trading decisions on eBay. The actual grading system depends on the type of item being graded. Authentication is a way of determining whether an item is genuine and described appropriately.
Authentication is very difficult because it relies on the expertise of the authenticators.
Because of their training and experience, experts can often easily detect counterfeits based on subtle details. However, two expert authenticators may have a different opinion about the authenticity of the same item. Verification is a way of confirming the identity and evaluating the condition of an item. Third parties will evaluate and identify an item through a variety of means. For example, some collectors have their item 'DNA tagged' for identification purposes.