In 2013, Adobe shifted entirely to a subscription-based model. Software could no longer be purchased outright; instead, users paid a monthly or annual fee to access the latest cloud-updated version.
In the retail era of software, physical boxed copies of Photoshop CS shipped with a unique, 24-digit alphanumeric serial number printed on the back of the CD jewel case. This key was required during installation to unlock the software. Adobe Photoshop CS 8 -serial included-
Focus on the "Fundamentals": Learning the Pen Tool and Layer Masks (which haven't changed in 20 years). In 2013, Adobe shifted entirely to a subscription-based