More specifically, you have choices if you're using a Mac (short for Macintosh, not MAC). Apple offers something called "Boot Camp" which allows you to partition your computer's hard disk into sections. One selection is used for macOS, the other for another operating system (usually Windows). After configured, when you boot, you can choose into which OS you want to use.

Another option is running another OS through virtualization, using software such as Parallels Desktop, Virtualbox, or VMware Fusion. This software emulates the computer hardware of another computer, which allows you to install another OS and run it alongside the mac OS. Parallels and VMware is commercial software; Virtualbox is free (open source).

I have been a user of Parallels for years. The current version (just shipped) is 13. I've been using it since v5! There are a number of benefits to running virtual machines opposed to Boot Camp. The primary benefit is being able to run multiple OSes simultaneously (Boot Camp is an "either-or" proposition). You can also be more flexible with disk space, as virtual machines can grow allocated disk space as needed. You can also change the memory and CPU allocations, meaning on an 8GB Mac, you can allocate 2GB to a Linux or Windows vm, and switch between them without chewing up all memory.

Personally, I only use my Windows and Linux vms when there is something I need to run that just isn't available on the Mac. These days, there isn't much that meets this criteria, so I'm mostly a Mac user. And happy about it.