the first operating operating system was used for work and the name of the operating system was GM-NAA I/O and it was invented by General Motors they made the ope rating system because they wnted it for ibm 704 http://internationalprogrammersday.org/history-of-operating-systems/

almost 26 years after the Microsoft has released a an OS called
MS-DOS after few days the company has renamed the operating system as the Quick-and-Dirty Operating System or Q-DOS. http://microsoft.wikia.com/wiki/MS-DOS

2 years after the release of MS-DOS, a new OS called the
MAC-OS which was released by the apple company. this Operating system has changed the way of the operating system like adding applications into the OS and also adding files and directories to the OS the founder was stive jobs. http://www.operating-system.org/betriebssystem/_english/bs-macos.htm

Later in 1995 Microsoft has released another OS called the windows OS it's actual name was windows 95 and it added the file directory and applications to the OS and they also added the Windows 95 came up with improved Graphical user interface and plug-n-play feature to this OS. http://www.windowsdatarecoverysoftware.com/win95/

The IOS is an OS with high security and was apple on January 9th, 2007 and this OS came in a phone called the i-phone but it had a lot of bugs when it was released like it didn't support multitasking, it didn't have a customizable home screen, it hid the file system from users, it didn't support voice dialing. you can say that apple was the first company to bring the smart phones to the outside world. http://www.theverge.com/2011/12/13/2612736/ios-history-iphone-ipad

after 1 year google released an OS called the android OS. THIS OS is getting grater and grater than the IOS because it is cheaper and also google gave the source code of the OS so you can make your own OS and customize the OS and many other things and its called android open source project. http://www.theverge.com/2011/12/7/2585779/android-history

this android version is called android nougat. this is released on This version has multiscreen, high graphics, speaks multi language, increased battery saving mode, secured and also open sourced. https://www.android.com/versions/nougat-7-0/