The new M1 silicon chip that Apple unveiled at its One More Thing event on Tuesday is the first of company’s new line of custom Arm-based silicon processors. These will utilize an ARM64 architecture — a departure from the x86–64 architecture found on the Intel chips Apple used previously. While this change will enable Macs to run iOS and iPadOS apps in addition to MacOS ones, it does prevent the new devices from running apps designed for the old Intel chips. So that’s why the company has released Rosetta 2.
“Rosetta is a translation process that allows users to run apps that contain x86-64 instructions on Apple silicon,” its developer page reads. “Rosetta is meant to ease the transition to Apple silicon, giving you time to create a universal binary for your app. It is not a substitute for creating a native version of your app.”