Distros will always be "Linux" and not their own operating systems

Today we have hundreds of distributions out available. Ubuntu, Fedora, openSUSE, Debian and many more. Many of them are based of each other. Ubuntu for instance is based on Debian, while OpenSUSE is based on Fedora. Despite the fact that they are all under the name of "Linux", most of these Operating Systems are leading their own development. Ubuntu, for instance, cannot use most of Debians .deb files anymore. Each of these distributions strive on their own to create and incorporate new OS level features such as networking, bluetooth, and other factors. However, all Linux distributions are based on the same Linux kernel. Unless they create their own kernel, or heavily modify the Linux kernel, they are all essentially the same Operating System.

Follow up:

A kernel is the bridge component that links the hardware to the software. It is often used to manage hardware, processing and much more.

The definition of a Linux Operating System is any Operating System that runs on the Linux Kernel. The Linux Kernel was created by Linus Torvalds in 1991 and was later developed into an operating system.

The common miss conception today is that different distributions of Linux are their own Operating System. This is commonly due to the fact that Red Hat based distributions (Such as OpenSUSE and Fedora)are based on RPM packages, while the Debian distributions are based on Deb. Even with this, it is not uncommon to see packages specifically single distribution, despite having the same package type. This is because the way the package is handled has branched off as it is not a kernel component. For example packages from Debian do not work in Ubuntu. In fact, some packages don't work within different versions of an operating system. This happens sometimes in versions leaps such as Ubuntu 6.10 and Ubuntu 7.10. In reality, the source code can be compiled on any distribution and run. The reason for packages not to work is because they may be installed differently. (An installation package is recompiled)

Almost all distributions have their own style of handling hardware options, networking, theme, search, drivers etc. Different distributions also handle aspects of an operating system that don't depend on the kernel. For instance once the kernel is booted, the operating system takes over by loading its necessary repositories. Package managers, GUI and software are all picked an tuned to the operating system.

However, despite the fact that distributions do differ from one another, the kernel is the same. This allows any code written for Linux to be compiled and run on any distribution. Unless the Linux kernel is developed or dropped for a different one, any distribution of Linux is virtually the same Operating System since it can run all the same software.

Winows XP and Windows 2000 can be seen as the same operating system, both based on the NT kernel. They hold their own options, features and programs. Things that are compiled on Windows XP can run on WIndows 2000, and the other way around.

Despite the fact that there are lots of distributions of Linux out there, they are virtually the same operating system and always will be. "What is the difference", you may ask. The difference is in the option and software that is available in that distribution. Usually meant for specific and general needs. So when picking, don't think its a different operating system, just pick the one that most suits you!