A checksum is a unique alphanumeric string that acts as a digital fingerprint for a file. By verifying the file you download against the known checksum, you can confirm it is uncorrupted and hasn't been tampered with.
The biggest hurdle to finding a legitimate is that Apple no longer lists it prominently in the App Store.
If the above fails (common on newer macOS versions), use (open-source): mac os x yosemite 10.10 5 download dmg
Before initiating the process, verify that your hardware can support this legacy system. Yosemite requires a minimum of 2 GB of RAM and at least 8 GB of available storage space (though 20 GB is recommended for real-world use).
Type your Mac’s administrator password (the characters won't show as you type) and press . A checksum is a unique alphanumeric string that
Press , type your Mac's administrator password (no characters will show on the screen as you type), and press Enter again.
Provide exact workarounds for creating the bootable installer on newer macOS versions If the above fails (common on newer macOS
7/10 (Historical Context)