3.     Linux:-

                Linux is a multi user, multi tasking, open source operating system first developed by Linux Benedict Torvalds in the year 1991. Linux is a 32 bit operating system. It runs on a wide variety of platforms, such Intel, Sparc, Alpha, etc.

               LINUX is an operating system or a kernel distributed under an open-source license. Its functionality list is quite like UNIX. The kernel is a program at the heart of the Linux operating system that takes care of fundamental stuff, like letting hardware communicate with software.

Linux Elements:-

Kernel –

            Kernel is the core part of Linux. It is responsible for all major activities of this operating system. It consists of various modules and it interacts directly with the underlying hardware. Kernel provides the required abstraction to hide low level hardware details to system or application programs.

Shell –

         Linux provides a special interpreter program which can be used to execute commands of the operating system. It can be used to do various types of operations, call application programs. etc. The shell takes commands from the user and executes kernel’s functions.

File System-

       Each file in the Linux is stored according to a particular sequence of directories. It uses forward slash(/) as a separator. All files and directories are connected to a root directory.