what is Ubuntu
Ubuntu is an entirely open source operating system built around the Linux kernel. The Ubuntu community is built around the ideals enshrined in the Ubuntu Philosophy: that software should be available free of charge, that software tools should be usable by people in their local language and despite any disabilities, and that people should have the freedom to customize and alter their software in whatever way they see fit. For those reasons:
Ubuntu will always be free of charge, and there is no extra fee for the “enterprise edition,” the best work is made for every individual and available to everyone on the same Free terms. —Canonical will actually ship Ubuntu CDs (worldwide) and pay for the shipping as well. Granted, these freely shipped CDs can take around two months to arrive, but you can’t really complain if you’re not paying for postage.