What is Linux?

The Linux kernel is the core of the operating system that facilitates between software and hardware.  The kernel is packaged alongside software created by other open-source developers into a 'distro' – or a distribution. 

Entire Linux distros can derive from other distros and create a family tree.  Debian is root of Ubuntu which is used in turn for Raspberry Pi OS, ElementaryOS, Linux Mint and many others.

Bootloader

Terminal or Console

Filesystem

 

Desktop Environment

Software freedom and equitable access are central tenets of many Linux distributions.  The decentralized development process is enabled by the open-source ethos of open knowledge sharing and peer participation.  Much of our modern world is powered through open-source software projects, such as openssl which acts as the backbone of the internet.