Linux is the free open-source operating system which means that the source code is provided with the system and can be edited. It comes under GPL i.e. General Public License which means you can always share it.
What is an operating system?
An operating system is a program that provides base for the application software and hardware etc.
What is Linux Kernel?
Kernel is a program that controls all the fundamental matter, manages hardware-software communication and hence it becomes the most important part of operating system.
The famous Linux distributions are: Red Hat, Novell, Debian and the latest one is Ubuntu. All distributions are having different flavors of Linux.
S A N G K R I T contemporarily recommends Ubuntu. Ubuntu is the version of Linux operating system, free to all like other versions of Linux; updates are also free of charge and provide particular user language too. Its developers pay a close attention towards desktop experience. It includes wide range of hardware drivers and everything you find in windows etc.