Linux is an operating system which is open for all and free to use in your system. It is too much similar to the other operating systems like Windows or Mac. Now the question is what is an operating system? An operating system is one kind of software which maintains all resources of the hardware exist in your laptop or computer. An operating system just like works as an interface between hardware and software. May be you have heard the word "cross-platform". Yeah, Linux is also cross-platform software this means that it runs on various computer model. Linux is an open source software because of its source code is openly shared with people and it can be free licensed to use, study, customize or change in your own way. You can customize the source code according to your specification. Linux is one of the most reliable and secure operating system worldwide because it can concentrate on process management strongly and offers excellent security for its users. Linux is actually everywhere. From smartphones to cars, supercomputers and home appliances. As like Windows or Mac, it can display graphics and several user-interface components. It has several flavors such as UBUNTU, Debian, Fedora, Red Hat and many more.