The open source model allows the freedom for anyone to view, modify, and distribute source code. The Linux kernel and the many distributions that uses it are released under any given open-source license which allows anyone to build their own Linux distribution at will.
Many Linux distributions are intended for home users.
This is a holding question for alternates dealing with long-obsolete Linux distributions, such as Red Hat Linux 9. Please do not split the alternates out. There is no reason to use these distributions; they no longer receive any security updates, may not run on modern hardware, and many modern Linux distributions are free.
The Linux kernel and the many off-shoot operating system distributions (Ubuntu, Linux Mint, and so on) are classed as open source and have nothing to do with Microsoft.
There are many ways to categorize Linux distributions. You can categorize them by their size, whether they run on a LiveCD, whether they are provided gratis, their ancestry of other Linux distros, and the purpose the distro is meant to serve.
There is no such thing as "Linux XP". If you're referring to Windows XP, then the answer is no. As far as Linux distributions, for the majority of distributions, they are free (as in freedom) and free-of-charge.
Most Linux distributions are free
There are no single Linux distribution that is based on Debian. In fact, there are many distributions based on Debian. This includes the ever-so-popular Ubuntu family, Devuan, AntiX, Crunchbang, and so on.
GCC is already for the most part preinstalled in many, if not all, GNU/Linux distributions.
Linux distributions can support hundreds of thousands of devices and programs, far too many to list.
There are so many different ways they can differ I can't really cover them all. Virtually anything in Linux distributions can be replaced. Even the kernel can be swapped out with alternate builds. Usually, the most common changes are the default desktop and desktop applications for desktop distributions.
There are many open-source OS distributions (distros) branching out from the Linux Kernel. Ubuntu, Linux Mint, Puppy, to name but three.
Most Linux distributions are available free of charge, so they do not require q product key to install.