Ubuntu is a free desktop operating system. It’s based on Linux, a massive project that enables millions of people around the world to run machines powered by free and open software on all kinds of devices. Linux comes in many shapes and sizes, with Ubuntu being the most popular iteration on desktops and laptops.
• Ubuntu "Ubuntu Tutorials are project-based, step-by-step guides to doing amazing things with Ubuntu. From installing the OS in the first place to packaging your first snap, we're here to help you on your way."
• Tutorials Point "This tutorial looks at the various aspects of the Ubuntu Operating system. It discusses various features, flavors, and working of the Ubuntu desktop edition. A comparison is made against software which we would normally find on a Windows operating system. There are chapters that focus on the server version of Ubuntu. This tutorial also includes separate chapters for those who are interested in understanding the virtual machines and cloud aspects of Ubuntu."
• Lifewire "Ubuntu (pronounced "oo-boon-too") is one of the most popular desktop Linux operating systems. The term Ubuntu derives from South Africa and roughly translates to "humanity toward others," a nod to the Ubuntu project's commitment to the principles of open-source software development. It is free to install and free to modify, although donations to the project are welcome."
• Make Use Of (MUO) "So you’re curious about Linux, and you heard Ubuntu is a great place to start? Maybe you’ve heard of Ubuntu and have no idea about this thing called Linux? Either way, you’ve come to the right place. This guide will teach you everything you need to know about Ubuntu in easy-to-understand language."