Ubuntu is a free and open source operating system that runs on desktops, laptops, and servers. It allows users to browse the web, send email, chat with friends, use office productivity tools like presentations and spreadsheets, play multimedia content, add and remove hundreds of free software packages with a secure package manager, and is available in over 40 languages with accessibility features and documentation. Ubuntu offers zero licensing fees, commercial and community support, customization, and certifications.