Secure Boot is a feature of your computer's UEFI that only allows approved operating systems to boot up.

Most computers come with just one operating system, which is usually all you need. However, if you feel like trying out a different one later, you don't need to get a whole new computer. Dual-booting ...

It is very normal to have multiple operating systems installed on a PC. If you need to use Linux and Windows for your work purposes or any other purposes, the obvious option you have is dual-booting ...