The COA is a sticker or a label that is attached to the retail packaging for products such as Windows, Office, or Windows Server. A COA should always accompany the product with which it is associated. COAs cannot be purchased separately. COA features the product name printed on the label and typically contains 3D Voiles™ and security threads. 3D Voiles are circular shaped areas where the COA varies in thickness and where an interwoven thread appears at the surface. Some older products contain Port-Holes™ and security threads (Port-Holes are small holes in the COA itself with uneven edges).
The product key label is an orange label that accompanies the installation CD/DVD and Certificate of Authenticity (COA) for a product and contains a 25-character product key. The words "Proof of License" appear on the label. The proof of license label cannot be purchased separately.
New Installation CD/DVD
Many Microsoft products on CD and DVD include holographic security features to help ensure you receive authentic product and to protect against counterfeiting.
Microsoft packaged software products such as Windows, Office, and Windows Server come on a holographic CD or DVD, commonly referred to as an edge-to-edge hologram disc, which shows vibrant color and 3D effects as the disc is tilted. This hologram is embedded within the disc; it is not a sticker.

Hologram Sticker
Note: The copper holographic material is embedded within the DVD and is not a sticker. If the hologram peels away, you may have received counterfeit software.
When viewing packaging, simple things like spelling errors, blurry text and images, or poor print quality can help you identify counterfeit software. Incorrect logos and photos that don't quite correspond to the product you're purchasing can also provide clues that something isn't quite right.