Require the assistance of other Adobe apps that might be 32bit, so you may experience difficulties with running Photoshop or whatever if you upgrade to Catalina. If you are running Adobe Creative Suite or single Adobe apps like Photoshop, Illustrator etc, some of these apps which are 64bit If you stay on Mojave or any other macOS 32bit apps will continue to work, you do not need to do anything. Quite simply it means that with the introduction of macOS Catalina in the fall 32 bit apps will not function in the new OS. This is probably the warning about 32bit apps, a lot of people are getting confused by this.
