What's an operating system ?

We deal with operating systems everyday on our phones, laptops,wearables,and even cars, but how does it really work and how can a company code an operating system ?
I will assure you that it's a long process that requires a lot of thinking, and visualizing interactions and how would people feel about it,becuase let's face it none of us would want to go back to Windows 1.0 or the classic Mac OS since they're so hard to deal with and it would take us hours just to write a word document on such an operating system.Oh wait ! you can't even do that because Microsoft office is such a hard program for an OS like the Mac OS X 1

What's an operating system ?

An operating system is the most important software that runs on a computer. It manages the computer's memory and processes, as well as all of its software and hardware. It also allows you to communicate with the computer without knowing how to speak the computer's language. Without an operating system, a computer is useless.

What does it do ? And how does it do it ?

An operating system communicates with the various parts of your computer. It sends information to and from your computer hardware and the desired application or action in order to carry out the tasks you request. The following pieces of equipment are in contact with your operating system:

• Keyboard
• Monitor
• Printer
• Mouse
• Disk drive

Your OS receives commands from you through some of these devices and then delivers it to the correct places to process your request.

Operating systems perform the following tasks:

• Recognize mouse click requests
• Register keyboard commands
• Deliver visual content
• Connect to printers, ports, drives, etc.
• Organize content

For the part of how does it do all of that, it's related to the engineering of computers they all have BIOS(Basic Input/Output System ) that are connected to the motherboards and every time we turn on our smart devices the bios takes the command and gives the lead to the OS 

References:

1-http://zdnet3.cbsistatic.com/hub/i/r/2015/07/23/db9b07b8-1bd3-4451-9365-7bd336f4d7dd/resize/1170x878/6a5511eafc6e9a454add33945466f8ed/cmwindows1-0jul15a.jpg

2-http://netdna.webdesignerdepot.com/uploads/2009/03/mac-os-1.gif