Great question — answering as the UphillTech team:
There are two options: Bootloaders - Bootloaders are executable code called by the computers BIOS. Typically these then load an operating system. Most Linux distributions use Grub2, however there are others. Windows uses the Windows Boot Manager. They are installed with the operating system, often overwriting any previous one. However, they are usually capable of booting other operating systems. I would recommend install Windows first, then install Linux. Grub2 will detect Windows and overwrite its Windows Boot Manager with Grub2, but will detect it and allow you to boot Windows. BIOS - You can install multiple operating systems and bootloaders on separate drives. Many BIOSs will let you...
Full answer by Keltari: https://superuser.stackexchange.com/a/1506438 (CC BY-SA 4.0).
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