INTRODUCTION: Smartphones, PADs, tablets and other portable devices used to run on the operating system are called mobile operating systems (Mobile OS). The specified data and programs that run on mobile devices are called mobile operating system. It manages all hardware and optimizes the performance of the device application software. Mobile multimedia functions, Internet connectivity and many other applications are managed by the mobile operating system. The basic infrastructure software inherent in a computerized system is the operating system. It controls all the primitive operations of the computer such as PDA and Smartphone. Installation and execution of third-party applications (called apps) by users is permitted on operating system devices. It lists the new features of the devices. Today, mobile devices with a desired operating system are called smartphones and a wide range of applications such as games, apps, communication or social media applications, digital maps, etc. are used. are used by users. There are several mobile operating systems such as: iOS, Android, BlackBerry. , Symbian OS, Bada OS, Windows OS, etc... In this audit, we introduce Windows operating system and Android operating system in brief. The features and applications of these phones were closely examined during the audit.TECHNOLOGIESAndroid:Android is an operating system used in smartphones. It is open source software. That is, the code is freely available under the Apache license for moderation and distribution by the device manufacturer. As we know that Android is open source software, so the manufacturer modifies it according to their needs and requirements from the user's point of view. In 2007, Android was first planned and it was the first time...... middle of paper ......Conclusion:-In this audit we compared two operating systems Windows and Android. Android phones are more efficient than Windows because it is an open source platform although it is not secure one can easily modify the code.References:-[1] G. Jindal, M. Jain , “A Comparative Study of Mobile Phone Operating Systems”, International Journal of Computer Applications and Information Technology, Vol. 1, issue 3, November 2012.[2] N. Gandhewar, R. Sheikh, “Google Android: Emerging Software Platform for Mobile Devices”, International Journal on ComputerScience and Engineering (IJCSE), ISSN: 0975-3397, pp. 12-17, 2010.[3] R. Rayarikar, S. Upadhyay, P. Pimpale, “SMS encryption using AESAlgorithm on Android”, International Journal of Computer Applications (IJCA), Vol. 50, No. 19, July 2012.