Older 32-bit apps still work in High Sierra, but this was the last version to support them "without compromises." If you rely on very old software, High Sierra is often the "Goldilocks" zone. Step 4: Creating a Bootable USB (Optional)
High Sierra (10.13) was designed to take the stability of 10.12.6 and modernize the core technologies. Key advancements included: macos high sierra 10.12.6 download