Ubuntu is a Debian-based Linux operating system, its default desktop environment is GNOME. It is based on free software.
From Wikipedia — named after the Southern African philosophy of ubuntu (literally, “human-ness”), which often is translated as “humanity towards others” or “the belief in a universal bond of sharing that connects all humanity”.
The standard Ubuntu Cd can be used as a Live Cd as well as an installer. Live mode is the default option when booting from CD. It gives the option of running a normal desktop environment with all the normal programs and some extras. A Live CD usually finds your wired internet connection.
Insert bootable disk in dvd/cd-rom
Automatic boot PC from dvd/cd-rom
After booting I hope you will see this installation process
Only click Try Ubuntu
If you see this installation process
only select Try Ubuntu without installing and press enter
Booting Ubuntu from dvd/cd-rom
This is Ubuntu live desktop