Operating Systems - the need for OS

The OS is the single most advanced and most efficient software that gets all the credit for making the computer hardware usable. The Operating System or OS is responsible for all the user friendliness of the computer.
Operating Systems is the first actual software that you need to install on your computers to be able to use it, including smartphones.
The functions of an OS include:

• Memory management
• Disk management
• File management
• Process management
• Interrupts and Networking

The OS runs and makes it possible for the users to interact with the computer without any knowledge about the underlying hardware. The OS interacts with the hardware using firmwares and device drivers and the users can use the hardware using the interface of the OS, called the GUI or Graphical User Interface.
A few features of modern operating systems are:

• GUI
• Multi-Threading
• Multi-Processing
• Multi-Tasking
• Multi-User

All other softwares that we use to do our work whether for office work, playing games, movies, music, browsing the internet, etc require the OS to support them. 

Examples of operating systems are Microsoft Windows XP, 7, 8, Mac OS X and Linux. A full list of operating systems may be found here.