Nothing induced panic like turning on the GPS enroute to find the error: "Database Mismatch. Insert Program Disc." This usually meant the firmware on the GPS had drifted, requiring the pilot to re-upload the operating system from the "Program" portion of the disc—a task impossible in flight.
The disc serves two main purposes depending on your subscription status: jeppesen program and data disc
The decline of the began around 2008 with the rise of three technologies: Nothing induced panic like turning on the GPS
(NavData). By 1996, the company introduced its massive library of aeronautical charts on —the predecessor to the modern Program and Data Disc. Modern Day: jeppesen program and data disc