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.

Ubuntu includes the very best in translations and accessibility infrastructure that the free software community has to offer, to make Ubuntu usable for as many people as possible.

Ubuntu is released regularly and predictably; a new release is made every six months. You can use the current stable release or the current development release. Each release is supported for at least 18 months.

Ubuntu is entirely committed to the principles of open source software development; we encourage people to use open source software, improve it and pass it on-Open source here means that the source code used in building Ubuntu and the many programs on it are non-proprietary which means that You won’t be bogged down with all sorts of licensing issues, and if you know something about programming, you can take a look at the source code of the applications and modify them as you see fit.

Ubuntu comes with a lot of productivity software—an office suite, a music player, a Photoshop-like graphics editor, an instant messaging program, an email client, an internet browser.And the are thousands of programs available in the community that can be used with Ubuntu.