In June 2021 Adobe released version 10.3 of Lightroom Classic, version 4.3 of Lightroom (cloud-based & mobile), and version 22.4.2 of Photoshop. Frequently, Adobe Photography Plan subscribers are confused about the differences between an update and an upgrade and how that affects the programs they use.
When a software company creates repairs for problems, or bugs, discovered as people use the program, the company usually makes fixes available for free. These don't change how the software operates, only patch things that proved not to work reliably with all computer systems. These changes, which for Adobe include bug fixes and adding support for new digital cameras and lenses, are called updates.
When a software company makes a major overhaul of their product, adding substantial new features, a new interface, and/or new programming behind the scenes, this results in a new, rewritten version of the software called an upgrade. In the days before software subscriptions, you had to pay additional money to gain access to the new features and programming in the upgrade.
The differences between updates and upgrades are reflected in the version numbers assigned to the software. I'll use Lightroom Classic as an example, but the idea applies to other software as well.
Currently, Lightroom Classic is at version 10.x. The "10" represents the newest version and the "x" represents an update. This is a newer, "rewritten" (behind the scenes) version of Lightroom Classic from the previous version 9.x. The latest release of Lightroom Classic changed the "x" in the version number 10 from 2 to 3.
For Lightroom Classic, a program update does not affect the format of your catalog. Everything under the hood in version 10.3 works the same as version 10.2. With the update to version 10.3 you are getting support for new cameras and lenses, repairs to bugs (problems) that have appeared, and some added features such as Super Resolution and a bevy of Develop module presets. (For a complete description of these update features, see Laura Shoe's summary here.)
When Adobe releases an upgrade to Lightroom Classic (or other applications in the Photography Plan), the software engineers have rewritten the code that creates and runs your Lightroom Classic catalog. In order to take advantage of the newly revised programming, you need to install the upgrade and also upgrade your catalog to work with the new version. This occurred in the past when Lightroom Classic went from version 9.x to version 10.x.
Check for Hardware Requirements
Software upgrades often change the hardware requirements needed to effectively run the application. So if you are using an older computer, you should check the system requirements before you upgrade your program. For this reason, I set my preferences in the Creative Cloud application (which manages software updates and upgrades) NOT to automatically update (or upgrade) my programs. Instead, Creative Cloud notifies me when updates and upgrades are available, giving me time to check on any hardware requirements I will need in order to take advantage of new features.
Often the updates bring more efficient processing speed along with resolving issues that made working with the program difficult for some people. So even if you disable automatic updates and upgrades for your Adobe subscription software, you should make a habit of checking on their requirements and installing them as soon as you know they will run on your system.