"linux" itself is an operating system. Distribution entities (link Redhat, ubunto, etc) take the operating and couple it with various (many) user space programs, libraries and other utilities and formulate a type of "distro". Each distro has a specific look, feel and mood to it, each of which appeals to different people.
Linux systems tend to far more robust than windows and more responsive. The kernel developers, examine, re-examine and refactor the kernel code to be clean, lean and easily readable (by programmers of course).
Take the case of USB devices, there is just one internal device driver model under linux to handle USB devices. Under windows, there are 3 different USB driver models that need to be maintained, because of the desire for backward compatibility of device drivers. Linux will change device driver interface (because the code is all there and can be refactored) but not the interface (system calls) to user programs. This allows linux change quickly and openly.
For one of the kernel releases, 2.6.22, there were 900 contributors.
For a good look at kernel development, look at
https://ols2006.108.redhat.com/2007/Reprints/kroah-hartman-Reprint.pdf
and look for Greg Kroah-Hartman's paper.
Linux runs on more different types of processors than any other OS (the feature that this helps is that the OS is well tested, and thus operates well on x86 type of processors). There are more device drivers for linux than other OSes. In some cases, they are out before Windows comes out. Yeah there are warts, but major drivers proceed along.
I run 6 computers at home on linux, and dual boot a Windows machine and a laptop. I also run Windows in a virtual partition under linux. (XEN). This is the way to get around dual booting - Always run linux, then startup a windows XEN virtual machine and run windows programs there. NO need to reboot.
It helps to expand one's horizon.
Admission: Old unix geek (1980) who used X-Windows long before Windows 3.1 existed. Now I love linux