The company's desire to banish 32-bit software and move everyone to modern, 64-bit versions is no secret and now it is starting the process of encouraging people to make the switch.
Apple indicated to developers at the 2017 Worldwide Developers Conference (WWDC) that High Sierra (10.13), the current version of macOS, will be the last version to support 32-bit apps "without compromise", though the specific meaning of that terminology is, as of yet, unclear.
With the new alert dialogue in macOS 10.13.4 going live, Apple is now informing customers about the upcoming requirement for 64-bit apps sometime in the future as well.
While this shift likely won't affect most people, if you're fond of a particularly old Mac app that hasn't been updated in a few years, that program could soon no longer be optimized for the latest version of Apple's desktop operating system. First, Apple notified developers, and then users, and stopped accepting app submissions to the App Store that were not 64-bit, before finally removing support entirely. Still, when the big day finally rolls around, there will nearly certainly be complaints nonetheless.
Further, the support page also explains to the users the advantages of using the 64-bit apps.
Apple is now pushing out notifications warning users that 32-bit app support will be dropped in an upcoming version of macOS. Next to a field "64-bit (Intel)', it will say "Yes" if it is a 64-bit app and 'No" if it's a 32-bit app.
Apple's next macOS major update will mark the end of the operating system's support for legacy 32-bit apps.
In the Finder, click on the Apple menu in the upper left and select About This Mac. "The developer of this app needs to update it to improve its compatibility." . The information will be displayed only once and won't include any mention of if or when exactly Apple will nix 32-bit application support from its operating system, according to Computerworld. The tech giant has been transitioning to the 64-bit hardware and software since last decade or so. However, it is believed that the 32-bit apps won't work as well as they use to before. The personal computer came with 64-bit PowerPC processors.
For now, the iPhone maker is just giving out warnings, and it has given no specific dates when the OS will totally stop supporting the 32-bit apps. When comparing the two, 64-bit is more efficient for it can access more memory and harness the power of newer technologies.